drm: msm: sde: Attempt DB DMA fallback if SB DMA not supported

The current implementation of DSPP GAMUT + IGC programming rely on
SBDMA for programming. This will cause GAMUT + IGC to be
unprogrammable on derivative Lahaina chipsets that do not have SBDMA
support.

Update the SBDMA handling to more intelligently check if SBDMA is
present, and fallback to DBDMA module where possible.

Change-Id: I89d07e38459ab59b96c69558178b8e97062ed93d
Signed-off-by: Christopher Braga <cbraga@codeaurora.org>