media: cx231xx: Fix Elgato Video Capture V2 default norm for PAL regions

The Elgato Video Capture V2 (card=16) has its default norm hardcoded to V4L2_STD_NTSC, causing rainbow-coloured scrambled image for users in PAL regions even when PAL is set via v4l2-ctl at runtime. Change the default norm to V4L2_STD_PAL to fix this. Tested on CachyOS with a JVC HR-J758 VCR in Norway.