Always define ARM_TSP_RAM_LOCATION_ID

ARM_TSP_RAM_LOCATION_ID was defined only in AARCH64, but the macro
was also used in AARCH32, and it meant that it was taking the value 0,
which happened to equal ARM_TRUSTED_SRAM_ID.

Change-Id: If9f4dbee1a2ba15e7806f2a03305b554bd327363
Signed-off-by: Roberto Vargas <roberto.vargas@arm.com>