staging: vt6655: Remove unused byRFType in card.c

Remove byRFType that support 5GHz band.

Signed-off-by: Philipp Hortmann <philipp.g.hortmann@gmail.com>
Link: https://lore.kernel.org/r/5554b243ae285e3274d9968575aadd1a79806b01.1646512837.git.philipp.g.hortmann@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>