staging: rtl8192e: Remove wireless modes A, N_5G from rtl92e_set_channel

Remove WIRELESS_MODE_N_5G and WIRELESS_MODE_A as those are not supported
by hardware and to improve readability.

Signed-off-by: Philipp Hortmann <philipp.g.hortmann@gmail.com>
Link: https://lore.kernel.org/r/aaaf832fe5f90ad2c618bef22c1bdbd5209c4359.1679949171.git.philipp.g.hortmann@gmail.com


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