V4L/DVB (7078): radio: fix sf16fmi section mismatch

isapnp_fmi_probe() is only called by fmi_init(), which is __init,
so isapnp_fmi_probe() can also be __init.

media/radio/radio-sf16fmi.c:
WARNING: vmlinux.o(.text+0x994e19): Section mismatch: reference to .init.data: (between 'isapnp_fmi_probe' and 'vidioc_s_tuner')
WARNING: vmlinux.o(.text+0x994e22): Section mismatch: reference to .init.data: (between 'isapnp_fmi_probe' and 'vidioc_s_tuner')
WARNING: vmlinux.o(.text+0x994e3a): Section mismatch: reference to .init.data:id_table (between 'isapnp_fmi_probe' and 'vidioc_s_tuner')

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>