defconfig: arm64: msmcortex: enable display xlog debug for msmcobalt

Enable display driver xlog debugging feature.
This feature enables MDSS registers dump during
display driver errors, panic during fatal errors and
logging of events in some key functions.
Events are light weighted, logged in an internal
ring buffer and buffer is only dumped during errors.

CRs-Fixed: 1048182
Change-Id: I2da2eba03ef30f3942ba3f8644efab98635002da
Signed-off-by: Ingrid Gallardo <ingridg@codeaurora.org>