Create AES implementation discovery API and program

[davidhorstmann-arm]

Part of implementing #9904

Create a simple function internal to TF-PSA-Crypto that provides information on the type of AES implementation that is selected and used. It should be declared in aes.h and defined in aes.c. It should return a value indicating which implementation of AES is being used (i.e. software AES, AESNI, AESCE, and whether intrinsics or assembly are being used).

Create a very simple program in TF-PSA-Crypto that calls the function to find out which AES implementation is used and prints out the result. This program will be used in testing to ensure that we are building and testing the correct AES implementation.

See also this comment in a discussion that originated this task.

Estimate: 6 IEH