[MTD] Make init_dbox2_flash static

The symbol init_dbox2_flash is not used outside of the file
drivers/mtd/maps/dbox2-flash.c, so make it static.

Signed-off-by: Dmitri Vorobiev <dmitri.vorobiev@movial.fi>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
1 file changed