west.yml: MCUboot synchronization from upstream

[nordicjm]

Update Zephyr fork of MCUboot to revision:
81315483fcbdf1f1524c2b34a1fd4de6c77cd0f4

• 81315483 Revert "zephyr: arm: Update reading the flash image reset vector"
• 47d826e7 boot: bootutil: swap_offset: Fix maximum application size
• d5d3359e zephyr: Fix trailer size computation for swap-scratch
• f9e4e529 zephyr: Fix TLV area was included in trailer size when rounding up
• 6cbea0a2 boot: boot_serial: Fix swap using offset
• efa30399 boot: bootutil: swap_move: Fix maximum application size

Notes on process:

1. The MCUboot update from mcu-tools/mcuboot/main with the SHA used in west.yaml is already synchronized to zephyrproject-rtos/mcuboot/upstream-sync branch, and is available in the Zephyr fork of MCUboot.
2. The [DNM] on this PR should be kept until the PR passes all tests and is accepted.
3. Once the PR passes all tests and gets accepted, the upstream-sync branch should be fast-forward merged to zephyrproject-rtos/mcuboot/main branch and [DNM] should be removed.
4. After the main branch gets updated, this PR does not require further changes and should be merged as is.

[github-actions]

The following west manifest projects have changed revision in this Pull Request:

Name	Old Revision	New Revision	Diff
mcuboot	zephyrproject-rtos/mcuboot@20f98e0	zephyrproject-rtos/mcuboot@8131548 (upstream-sync)	zephyrproject-rtos/[email protected]

✅ All manifest checks OK

Note: This message is automatically posted and updated by the Manifest GitHub Action.

[nashif]

This still has the build issue with tfm:

ash_area_get_sectors'? [-Wimplicit-function-declaration]
  152 |         ret = flash_area_get_sector(fa, flash_area_get_size(fa) - boot_trailer_sz(alignment),
      |               ^~~~~~~~~~~~~~~~~~~~~
      |               flash_area_get_sectors

[nordicjm]

This still has the build issue with tfm:

ash_area_get_sectors'? [-Wimplicit-function-declaration]
  152 |         ret = flash_area_get_sector(fa, flash_area_get_size(fa) - boot_trailer_sz(alignment),
      |               ^~~~~~~~~~~~~~~~~~~~~
      |               flash_area_get_sectors

That is a TF-M issue that needs fixing in TF-M, in TF-M they use parts of MCUboot code as "bl2" and do not define that function in a header file as they should, hence the warning