ANDROID: GKI: add ww_mutex_trylock to db845c symbol list

In commit f3d4fa12 ("drm/msm: use trylock for debugfs"), the msm drm
driver switches to use ww_mutex_trylock, so add it to the db845c symbol
list to fix up the build.

Fixes: 6e8421d4 ("drm/msm: use trylock for debugfs")
Change-Id: I2a67a7099245ebad1d4f8b96c54b59b78bdc7ba8
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>