staging: rtl8723bs: convert function name to snake case

convert Hal_GetChnlGroup8723B() function name to snake
case.

Signed-off-by: Fabio Aiuto <fabioaiuto83@gmail.com>
Link: https://lore.kernel.org/r/78bbc5cb8531bc03eccfa2f67ee71979cbfbf12e.1626874164.git.fabioaiuto83@gmail.com


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