staging: bcm2835_codec: Pass framerate to the component if set late

For video encoding, if the framerate was set after the component
was created, then it wasn't set correctly on the port, and an
old value was encoded in the bitstream.

Update the port status when the framerate is set.

https://github.com/raspberrypi/rpicam-apps/issues/664



Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>