libcaliptra ARRAY_SIZE define conflicts with other defines of the same name

[nquarton]

A user has reported their SoC FW already has "ARRAY_SIZE" defined with a equivalent implementation and this causes a conflict while building with libcaliptra.

The easiest solution (without assuming an existing implementation will always be the same) is to make the ARRAY_SIZE name unique as CALIPTRA_ARRAY_SIZE.