cros_gralloc_driver: init_master: set try_generic argument to true

cros_gralloc_driver: init_master: set try_generic argument to true

Fixes the following building error:

external/minigbm/cros_gralloc/cros_gralloc_driver.cc:169:10: error: no matching function for call to 'drv_create'
                drv_ = drv_create(fd);
                       ^~~~~~~~~~
external/minigbm/drv.h:122:16: note: candidate function not viable: requires 2 arguments, but 1 was provided
struct driver *drv_create(int fd, bool try_generic);
               ^
1 error generated.

Change-Id: I82555ecfd96d7e6ab5423a0640c410118ee77c4f