drm/i915: Avoid PPS HW/SW state mismatch due to rounding

drm/i915: Avoid PPS HW/SW state mismatch due to rounding

We store a SW state of the t11_t12 timing in 100usec units but have to
program it in 100msec as required by HW. The rounding used during
programming means there will be a mismatch between the SW and HW states
of this value triggering a "PPS state mismatch" error. Avoid this by
storing the already rounded-up value in the SW state.

Note that we still calculate panel_power_cycle_delay with the finer
100usec granularity to avoid any needless waits using that version of
the delay.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=103903
Cc: joks <joks@linux.pl>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171129175137.2889-1-imre.deak@intel.com