msm: mdss: Avoid delay in framebuffer registration

Change framebuffer driver init to 'module_init' to
make framebuffer registration to happen earlier. This is
needed for few configurations where we want
to display image as soon as the kernel starts booting.

Change-Id: Ibe7cda8304a9e16ee50a3043b822517a71a23498
CRs-Fixed: 453847
Signed-off-by: Chandan Uddaraju <chandanu@codeaurora.org>