GPU Overclock: initial GPU overclocking to 487.5 MHz

Signed-off-by: Paul Reioux <reioux@gmail.com>

Conflicts:
	arch/arm/mach-msm/Kconfig
GPU Overclocking: add 450 MHz option

Signed-off-by: Paul Reioux <reioux@gmail.com>

Conflicts:
	arch/arm/mach-msm/clock-8960.c

Conflicts:
	arch/arm/mach-msm/Kconfig

Conflicts:
	arch/arm/mach-msm/Kconfig
GPU overclocking: port to v500
defconfig: update
kgsl: enable gpu clock store