MA-12288-1[Android] Fix the minimum clock cannot align with gpu3DMinClock

The minimum clock of GPU is variable and can be set through sysfs file
/sys/bus/platform/drivers/galcore/gpu3DMinClock. This value should read every
time when thermal event generated.
The original scale of GPU frequence is the one when boot up.

Change-Id: I6f1786ae46403d216f3f6dbf715c1aa332cd3351
Signed-off-by: Zhang Bo <bo.zhang@nxp.com>