Merge changes from topic "for_lts_v2.8.20" into lts-v2.8
* changes:
docs(prerequisites): update mbedtls version used
feat(mbedtls): update config for 3.6.0
refactor(mbedtls): remove mbedtls 2.x support
build(mbedtls): add deprecation notice
feat(mbedtls): update to 3.4.1
docs(prerequisites): update software and libraries prerequisites
feat(stm32mp1): add mbedtls-3.3 support config
refactor(fvp): minor cleanup with TRUSTED_BOARD_BOOT
feat(fvp): increase BL1_RW and BL2 size
feat(mbedtls): add support for mbedtls-3.3
refactor(mbedtls): avoid including MBEDTLS_CONFIG_FILE
feat(build): allow additional CFLAGS for library build
chore: add encrypt_fw to gitignore