disp: msm: add msm framebuffer emulation

This change copies msm_fbdev.c from msm-5.14 kernel, which adds
frame buffer support to display driver. And this file is from
msm-5.4 commit <5fce077d> ("drm: msm: Fix the format prints in
display driver").

Change-Id: I113cb6441334ff6b61cfd15cf863c325d51091b4
Signed-off-by: Kai Xing <quic_kxing@quicinc.com>