[media] Sensoray 2255 uses videobuf2

commit 340a30c5 "s2255drv: upgrade to videobuf2" changed the API
used by the s2255 driver, but did not modify the Kconfig statement,
which can lead to build errors when no other driver already uses
VIDEOBUF2_VMALLOC. This patch does the necessary Kconfig change.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>