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>
Signed-off-by: Francisco Franco <franciscofranco.1990@gmail.com>
cpufreq: interactive: instead of bumping the target_cpu freq to the source_cpu current freq make it boost to SYNC_FREQ instead at 960MHz (maybe configurable in the future?) and that should be enough and help with the performance/battery ratio.

Signed-off-by: Francisco Franco <franciscofranco.1990@gmail.com>

Conflicts:
	drivers/cpufreq/cpufreq_interactive.c