staging: bcm2835-camera: remove anonymous field declarations

Anonymous field declarations are error prone. This patch replaces
anonymous declarations with explicit field declarations for typedef
SERVICE_CREATION_T in vchiq_mmal_init(..)

Signed-off-by: Aishwarya Pant <aishpant@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>