configs: Add PWM=y and NFSD_V2=y

All the PWM drivers are now gated by CONFIG_PWM, so add that.
Similarly, NFSD_V2_ACL requires NFSD_V2.

Regenerating the defconfigs also acknowledges the loss of
CONFIG_CDROM_PKTCDVD and CONFIG_NFT_OBJREF.

Signed-off-by: Phil Elwell <phil@raspberrypi.com>