drm:msm:sde: enable sde client customization

Sde client customization is disabled by previous commit which
is propagated from other branch. After disabling this, 4K display
on HDMI can not be up. This is because when creating drm plane in kernel,
sde client customization will directly set possible_crtcs per plane
reporting to user space. When disabling it, user space's sdm strategy
could not get and assign correct pipes for 4K display.

Change-Id: Ie6a870c352533060f7c810bdb5c99b7c1534117d
CRs-fixed: 2107328
Signed-off-by: Guchun Chen <guchunc@codeaurora.org>