msm: Kconfig: Select ARM_HAS_SG_CHAIN for 7627a/8625

ION allocations in SYSTEM_HEAP now uses alloc_pages() and not
vmalloc(). This will add one entry into sg_table for each page
of allocation. With this, sg_table may over-cross the limit
of fitting into one page for bigger sized allocations. So,
accommodate extended sg_table entries by chaining more pages.

ARCH_HAS_SG_CHAIN will enable this chain of pages. Enable
ARM_HAS_SG_CHAIN to select ARCH_HAS_SG_CHAIN.

Change-Id: Ia1316c99478ef72afc3e43bdc67c352141a583ee
Signed-off-by: Chintan Pandya <cpandya@codeaurora.org>