drm/via: Fix vblank IRQ on VIA hardware.
drm/via: Fix vblank IRQ on VIA hardware.

via_enable_vblank wasn't setting the VBlank enable bit - instead, it
was masking out the rest of the register.

At the same time, fix via_disable_vblank to clear the VBlank enable
bit.

Signed-off-by: Dave Airlie <f2295d84e358395675bc8031be58672073ae065e@linux.ie>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs