This renames rtl8723b_channel_to_group() to
rtl8xxxu_gen2_channel_to_group() to reflect it is used by all
currently supported gen2 parts.
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>