drm/i915: Fix gen2 planes B and C max watermark value
drm/i915: Fix gen2 planes B and C max watermark value

The max watermark value for gen2 planes B and C is 0x1f, instead of
the 0x3f that plane A uses.

Also check against the max even if the pipe is disabled since the
FIFO size exceeds the plane B and C max watermark value.

Signed-off-by: Ville Syrjälä <cd6e8d405ca90be3a03d5427c5b24fbd2d68dcc4@linux.intel.com>
Tested-by: Thomas Richter <85767d69b748effcccb22be95ac249e22c8f6bd4@rus.uni-stuttgart.de>
Signed-off-by: Daniel Vetter <c1b6782c4af8f0673da8923a0702a1832e5940f4@ffwll.ch>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs