Implement EFI capsule update functionality for PHYTEC K3-based SoMs.
These SoMs feature various flash device options, including eMMC,
OSPI NOR, and uSD card at the board level.

This update provides the necessary logic to enable EFI capsule updates
across all three flash devices, ensuring flexible and robust firmware
upgrade capabilities.

The GUID is dynamically generated for the board, to get it:

  efidebug capsule esrt
  ========================================
  ESRT: fw_resource_count=3
  ESRT: fw_resource_count_max=3
  ESRT: fw_resource_version=1
  [entry 0]==============================
  ESRT: fw_class=C7D64D6D-10B2-54BC-A3BF-06A9DC3653D9
  ESRT: fw_type=unknown
  ESRT: fw_version=0
  ESRT: lowest_supported_fw_version=0
  ESRT: capsule_flags=0
  ESRT: last_attempt_version=0
  ESRT: last_attempt_status=success
  [entry 1]==============================
  ESRT: fw_class=09841C3F-F177-5D57-B1F6-754D92879205
  ESRT: fw_type=unknown
  ESRT: fw_version=0
  ESRT: lowest_supported_fw_version=0
  ESRT: capsule_flags=0
  ESRT: last_attempt_version=0
  ESRT: last_attempt_status=success
  [entry 2]==============================
  ESRT: fw_class=D11A9016-515E-503A-8872-3FF65384D0C4
  ESRT: fw_type=unknown
  ESRT: fw_version=0
  ESRT: lowest_supported_fw_version=0
  ESRT: capsule_flags=0
  ESRT: last_attempt_version=0
  ESRT: last_attempt_status=success
  ========================================

On the board (from uSD card containing capsule binaries at boot):

  load mmc 1:1 $loadaddr tiboot3-capsule.bin
  efidebug capsule update $loadaddr

  load mmc 1:1 $loadaddr tispl-capsule.bin
  efidebug capsule update $loadaddr

  load mmc 1:1 $loadaddr uboot-capsule.bin
  efidebug capsule update $loadaddr

The binaries will be flashed to the flash device you are booted from.

Signed-off-by: Wadim Egorov <w.egorov@phytec.de>

Add basic support for PHYTEC phyCORE-AM62x SoM.

Supported features:
  - 2GB DDR4 RAM
  - eMMC Flash
  - OSPI NOR Flash
  - external uSD
  - Ethernet
  - debug UART

Product page SoM: https://www.phytec.com/product/phycore-am62x

Device trees were taken from Linux v6.7-rc3.

Signed-off-by: Wadim Egorov <w.egorov@phytec.de>
Reviewed-by: Dhruva Gole <d-gole@ti.com>