drm/radeon/kms: fix up gpio i2c mask bits for r4xx for real

drm/radeon/kms: fix up gpio i2c mask bits for r4xx for real

commit d724502a9d7a46f4a56a1663b1f50d2dc9d1ef40 upstream.

Fixes i2c test failures when i2c_algo_bit.bit_test=1.

The hw doesn't actually require a mask, so just set it
to the default mask bits for r1xx-r4xx radeon ddc.

I missed this part the first time through.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>