defconfig: arm: setting mmap_rnd_bits

Update mmap_rnd_bits to max value.

Change-Id: Ibba0cdddddae76d9e1106907dbb5f96135726d85
Git-commit: 98437587fbd2f9c407125872ef5798ee04ad12c0
Git-repo: https://android.googlesource.com/kernel/msm.git


[schikk@codeaurora.org similar change added for 64-bit defconfig]
CRs-Fixed: 1058121
Signed-off-by: Swetha Chikkaboraiah <schikk@codeaurora.org>