media: ti-vpe: cal: Use spin_lock_irq() when starting or stopping stream

The cal_start_streaming() and cal_stop_streaming() functions are called
with interrupts enabled. spin_lock_irq() can thus be used instead of
spin_lock_irqsave().

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Benoit Parrot <bparrot@ti.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>