[media] solo6x10: don't turn off/on encoder interrupt in processing loop

It makes no sense to block the SOLO_IRQ_ENCODER interrupt from being sent while
processing an earlier interrupt. New interrupts will just kick the thread
again once it is done processing.

Signed-off-by: Andrey Utkin <andrey.krieger.utkin@gmail.com>
[hans.verkuil@cisco.com: fix commit description]
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>