V4L/DVB (7882): pvrusb2: make code static

This patch makes the following needlessly global code static:
- pvrusb2-devattr.c: struct pvr2_onair_creator_fe_props
- pvrusb2-devattr.c: struct pvr2_onair_usb2_fe_props
- pvrusb2-devattr.c: struct pvr2_73xxx_dvb_props
- pvrusb2-devattr.c: struct pvr2_750xx_dvb_props
- pvrusb2-devattr.c: struct pvr2_751xx_dvb_props
- pvrusb2-hdw.c:pvr2_led_ctrl_hauppauge()

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Mike Isely <isely@pobox.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>