portable: remove stray installer URL from IAR TrustZone non-secure ports - #1492

Problem

A stray IAR installer download URL sits outside the comment delimiters in the
restore_special_regs section of the IAR TrustZone non-secure ports:

        ldmia r2!, {r0, r3, lr}             http://files.iar.com/ftp/pub/box/bxarm-9.60.3.deb/* Read from stack - r0 = xSecureContext, r3 = PSPLIM and LR restored. */

Because /* appears after the URL, the assembler reads the bare URL as an operand
of the preceding ldmia and aborts:

Error: garbage following instruction -- `ldmia r2!,{r0,r3,lr} http:'

Note the line sits outside the #if ( configENABLE_PAC == 1 ) block (which ends
on the preceding line), so it breaks every configuration of these ports, not only
PAC-enabled builds.

Scope

Issue #1480 reports this for portable/IAR/ARM_CM33/non_secure/portasm.s.

A tree-wide scan of main (8be86d4) finds the stray URL in 7 files, all at
line 476. #1485 fixes one of them; this PR fixes the remaining six, so the two PRs
form a clean 1 + 6 partition with no file overlap and may merge in either order.
The six files:

• portable/ARMv8M/non_secure/portable/IAR/ARM_CM33/portasm.s
• portable/IAR/ARM_CM35P/non_secure/portasm.s
• portable/IAR/ARM_CM52/non_secure/portasm.s
• portable/IAR/ARM_CM55/non_secure/portasm.s
• portable/IAR/ARM_CM85/non_secure/portasm.s
• portable/IAR/ARM_STAR_MC3/non_secure/portasm.s

portable/IAR/ARM_CM33/non_secure/portasm.s is intentionally excluded because
#1485 already addresses it.

Note there are two distinct CM33 assembly files in the tree, both affected, and they
are easy to confuse:

Fix

The stray URL is deleted, and the comment keeps its original text and column alignment:

-        ldmia r2!, {r0, r3, lr}             http://files.iar.com/ftp/pub/box/bxarm-9.60.3.deb/* Read from stack - r0 = xSecureContext, r3 = PSPLIM and LR restored. */
+        ldmia r2!, {r0, r3, lr}             /* Read from stack - r0 = xSecureContext, r3 = PSPLIM and LR restored. */

This matches the unaffected sibling port portable/IAR/ARM_CM23/non_secure/portasm.s
(line 444), which carries the same comment text without any URL. Optionally the URL
could be kept inside the comment instead, as #1485 does — either form assembles; I
removed it because it is a meaningless installer link.

Origin

Commit 78e0cc7 ("ARMv8.1-M: Add task dedicated PAC key support", #1195) introduced the
URL into CM33, CM35P, CM55, CM85 and the ARMv8M non-secure port. The CM52 (#1334) and
STAR-MC3 (#1363) ports were later created from an already-affected portasm.s and
inherited it.

Verification

Assembled with arm-none-eabi-gcc 13.3.1 20240614 (GNU Tools for STM32 13.3.rel1).
IAR's own directives (PUBLIC / EXTERN / SECTION / THUMB / END) were translated
1:1 to GNU equivalents so that the only difference between the "before" and "after"
inputs is the one comment line, making the result attributable to it.

Baseline (known-good sibling, proves the harness accepts a healthy file):

portable/IAR/ARM_CM23/non_secure/portasm.s   ->  assembles OK

All six files in this PR:

RESULT: 6/6 files assemble cleanly, 0 stray URLs remaining.

Caveat, stated plainly: the check ran on GNU as, not on IAR iccarm (no IAR
licence available here). Both reject a bare token after an instruction, and the
reporter of #1480 reproduced the failure on IAR ARM 9.70.2, so the defect and the fix
are cross-confirmed — but this is not an IAR build.

Note on CI

.github/workflows/kernel-demos.yml only builds the CORTEX_MPS2_QEMU_IAR_GCC demo,
which is compiled with GCC. The IAR ports are not built by CI at all, which is how this
slipped through. Adding an assembler-only syntax check for these ports would be a
separate, larger change — happy to look at it if you think it is worth doing.

Relates to #1480.