bsps/arm: Init trans tbl with invalid entries
bsps/arm: Move some MMU bit settings

The function
arm_cp15_start_setup_translation_table_and_enable_mmu_and_cache() must
only set the MMU and cache enable flags.  Configuration flags must be
set elsewhere.
Modify raspberrypi mm_config_table to map GPIO and registers.

Changes include reverting back to setting all page-table section entries
as invalid and modify mm_config_table to apply the correct memory attributes
for raspbberypi memory sections at startup. The newly added entry at mm_config_table
maps raspberrypi GPIO and other registers found at raspberrypi.h