msm_fb: display: enable hw cursor for dsi video panel

fix hw cursor updates not coming for dsi video panel defining callback
during driver setup.

CRs-Fixed: 309515
Change-Id: I12586e813c19ff4dbe1e3877eaf14b5a396b273a
Signed-off-by: Adrian Salido-Moreno <adrianm@codeaurora.org>