ARM: vfp: only clear vfp state for current cpu in vfp_pm_suspend

vfp_pm_suspend runs on each cpu, only clear the hardware state
pointer for the current cpu.  Prevents a possible crash if one
cpu clears the hw state pointer when another cpu has already
checked if it is valid.

Change-Id: I997ab1554944eba86730818ff242d7ebe1b32736
Signed-off-by: Colin Cross <ccross@android.com>