drm/i915: Fix VLV eDP timing v2

Fix the typo in previous commit for DP 1.62 divisor.
drm/i915: Move Valleyview DP DPLL divisor calc to intel_dp_set_clock v2

v2: sigh, the m1 div is 3.

Reported-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Chon Ming Lee <chon.ming.lee@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>