ARM: Use -mcpu=cortex-a15 when targeting MSM Krait CPUs

Enable compiler optimizations specific to the Cortex-A15
processor when targeting MSM Krait CPUs. This is necessary
take advantage of the UDIV/SDIV instructions supported by
these processors. To accomplish this, we need to remove the
-march=armv7-a ISA restriction from the compiler options
because 'cortex-a15' is a superset of 'armv7-a'.

Change-Id: I6215aecc11fb4f77c971de7b84f68649ef234357
Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>
ghost: Default to NOOP scheduler in-kernel

Just extra checks for paranoia. Settings are actually already in ramdisk.

Signed-off-by: Zhao Wei Liew <zhaoweiliew@gmail.com>
mm: Increase readahead value to 512kB in-kernel

Just for paranoia. Settings already in ramdisk.

Signed-off-by: Zhao Wei Liew <zhaoweiliew@gmail.com>