cx88-dsp: fixing 64bit math on 32bit kernels

Some gcc versions report the missing of __divdi3

[mchehab.redhat.com: CodingStyle fixes]
Signed-off-by: Miroslav Sustek <sustmidown@centrum.cz>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>