defconfig: msm: update mmap randomness for all targets

CTS malloc tests on Android 'N' expects higher entropy in
mmap returned address. Present value of mmap random bits
is not providing enough variations for 32 bit tasks.

Increase mmap_rnd_bits for 32bit and mmap_rnd_compat_bits
for 64bit targets to value of 16.

Change-Id: Ibf6463467f28221470619b4f43ece062d41ae6b8
Signed-off-by: Shiraz Hashim <shashim@codeaurora.org>