samples: net: wifi: shell: split rw612 conf file

Keep the minimum configurations in frdm_rw612.conf and rd_rw612_bga.conf
for basic STA functionality of embedded supplicant case.
Add the superset configurations in nxp/overlay_rw612.conf.
Add the supplicant support in nxp/overlay_hostap_rw612.conf.
Add the basic debug support in nxp/overlay_rw612_debug.conf.
Add the supplicant debug support in nxp/overlay_hostap_rw612_debug.conf.

Signed-off-by: Maochen Wang <maochen.wang@nxp.com>