feat(stm32mp1): add the decryption support

Add the decryption support for STM32MP1 binaries.
Decryption is limited to the BL32 loaded images.

Limitation: STM32MP15 doesn't support the feature.

Change-Id: I96800bac7b22109f8471eb2953fc0dc269fc4fd1
Signed-off-by: Lionel Debieve <lionel.debieve@foss.st.com>
5 files changed