ARMv7: support non-LPAE mapping (not xlat_v2)

Support 32bit descriptor MMU table. This is required by ARMv7
architectures that do not support the Large Page Address Extensions.

nonlpae_tables.c source file is dumped from the OP-TEE project:
core_mmu_armv7.c and related header files.

Change-Id: If912d66c374290c49c5a1211ce4c5c27b2d7dc60
Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>
Signed-off-by: Usama Arif <usama.arif@arm.com>