video: fbdev: msm: build msm driver when dba is enabled

MSM fbdev driver contains both mdss and dba drivers. It needs to be
compiled when either one of them is enabled.

Change-Id: I6a62b99dddce4da0485d34bca11704aeb9064465
Signed-off-by: Jin Li <jinl@codeaurora.org>
Signed-off-by: Yunyun Cao <yunyunc@codeaurora.org>