ENGR00215344 GPU became slow after long time run some applications

ENGR00215344 GPU became slow after long time run some applications

GPU became slow after long time run some applications
root cause is when GPU reserved memory exhaust, GPU will request continue physical
memory which will trigger defregment operation in kernel and cause system slow

Signed-off-by: Richard Liu <r66033@freescale.com>
Acked-by: Lily Zhang