kasan_pte_populate fill KASAN_SHADOW_INIT in the newly
allocated shadow page, so it's unnecessary to
use memblock_alloc_try_nid, which always zero the
new allocated memory.

Use memblock_alloc_try_nid_raw instead of
memblock_alloc_try_nid like arm64 does which
can make kasan init faster.
Signed-off-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>