KGSL GPU OC: Fixed mess for my kernel.

*I was getting freq 27Mhz (lvl 7) set on high temp. that lead to gpu stall.

Now all OK.

@neoboddy89 please check this. you too have the same amount of freqs for GPU.
you need to corect this.!

num of gpu freqs is 8! not 7 (0-7) as 7 is the 27mhz we cant really use it
for GPU!
so we must lock min to 6.