refactor(measured-boot): avoid Measured-Boot dependency on Trusted-Boot

refactor(measured-boot): avoid Measured-Boot dependency on Trusted-Boot

Measured-Boot and Trusted-Boot are orthogonal to each other and hence
removed dependency of Trusted-Boot on Measured-Boot by making below
changes -
1. BL1 and BL2 main functions are used for initializing Crypto module
   instead of the authentication module
2. Updated Crypto module registration macro for MEASURED_BOOT with only
   necessary callbacks for calculating image hashes
3. The 'load_auth_image' function is now used for the image measurement
   during Trusted or Non-Trusted Boot flow

Change-Id: I3570e80bae8ce8f5b58d84bd955aa43e925d9fff
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>