sp: align stack pointer

According to ARM ARM, stack pointer has to be 16 byte aligned. Since
__stack_end is where the stack pointer is initialized, it has to be
16 byte aligned.

Signed-off-by: Davidson K <davidson.kumaresan@arm.com>
Change-Id: Ie93bf91459c96f4147c36f22f2d9b758057cd80e
1 file changed