Revert "Remove 51 mhz cpu step"

This reverts commit 05bb91ea92fe05b6f2c52bdbe91d15feceb98302.
mach-tegra: pm: fix wrong awake cpufreq

Signed-off-by: Dennis Rassmann <showp1984@gmail.com>
Added V(R) I/O Scheduler

Conflicts:
	block/Kconfig.iosched
	block/Makefile