media: pisp-be: Backport the mainline PiSP BE driver

Backport to rpi-6.6.y the mainline version of the PiSP BE driver.

The backported version of the driver corresponds to the one available
at:
https://lore.kernel.org/all/20240626181440.195137-1-jacopo.mondi@ideasonboard.com/



Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>