V4L/DVB (13980): [STV6110x] Added function stv6110x_write_regs

The function stv6110x_write_regs is used to write several registers at once.

Signed-off-by: Andreas Regel <andreas.regel@gmx.de>
Signed-off-by: Manu Abraham <manu@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>