video/hpfb.c section fix

WARNING: vmlinux.o(.text+0xb851a): Section mismatch: reference to .init.text:hpfb_init_one (between 'hpfb_dio_probe' and 'read_null')

hpfb_init_one() must be __devinit since it's called by the __devinit
hpfb_dio_probe().

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>