plat/arm: Reduce size of BL31 binary

plat/arm: Reduce size of BL31 binary

BL31 binary size is aligned to 4KB because of the
code in include\plat\arm\common\arm_reclaim_init.ld.S:
    __INIT_CODE_UNALIGNED__ = .;
    . = ALIGN(PAGE_SIZE);
    __INIT_CODE_END__ = .;
with all the zero data after the last instruction of
BL31 code to the end of the page.
This causes increase in size of BL31 binary stored in FIP
and its loading time by BL2.
This patch reduces the size of BL31 image by moving
page alignment from __INIT_CODE_END__ to __STACKS_END__
which also increases the stack size for secondary CPUs.

Change-Id: Ie2ec503fc774c22c12ec506d74fd3ef2b0b183a9
Signed-off-by: Alexei Fedorov <Alexei.Fedorov@arm.com>