drm/i915: don't rely on previous values when setting LPT TRANSCONF
drm/i915: don't rely on previous values when setting LPT TRANSCONF

Because we already set all the bits we can set.

Signed-off-by: Paulo Zanoni <cc0e04a2103c45cd195651d976f79813d0f66bdf@intel.com>
[danvet: apply by hand due to dropped patch. Also, obey my OCD a bit
and do a s/_TRANSACONF/TRANSCONF(TRANSCODER_A)/, makes it more
consisten with other lpt pch code imnsho ...]
Signed-off-by: Daniel Vetter <c1b6782c4af8f0673da8923a0702a1832e5940f4@ffwll.ch>

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