Present framework restricts platform to pass desired shareability attribute
for normal memory region mapped in MMU. it defaults to inner shareability.

There are platforms where memories (like SRAM) are not placed at snoopable
region in advaned interconnect like CCN/CMN hence snoopable transaction is
not possible to these memory. Though These memories could be mapped in MMU
as MT_NON_CACHEABLE, data caches benefits won't be available.

If these memories are mapped as cacheable with non-shareable attribute,
when only one core is running like at boot time, MMU data cached could be
used for faster execution. Hence adding support to pass the shareability
attribute for memory regions.

Signed-off-by: Pramod Kumar <pramod.kumar@broadcom.com>
Change-Id: I678cb50120a28dae4aa9d1896e8faf1dd5cf1754