defconfig: Lahaina: enable external display module

Enable the external display module, which is a utility
to manage display interface and audio codec interactions
associated with the cable connect/disconnect events of the
display interfaces.

Change-Id: I736e86320f5a29c67cb3ca7a2f23429f07fe9445
Signed-off-by: Tatenda Chipeperekwa <tatendac@codeaurora.org>