[media] solo6x10: fix a race in IRQ handler

The IRQs have to be acknowledged before they are serviced, otherwise some events
may be skipped. Also, acknowledging IRQs just before returning from the handler
doesn't leave enough time for the device to deassert the INTx line, and for
bridges to propagate this change. This resulted in twice the IRQ rate on ARMv6
dual core CPU.

Signed-off-by: Krzysztof Ha?asa <khalasa@piap.pl>
Acked-by: Andrey Utkin <andrey.utkin@corp.bluecherry.net>
Tested-by: Andrey Utkin <andrey.utkin@corp.bluecherry.net>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>