staging: rtl8723bs: remove unused file hal_phy.c

Remove the unused file hal_phy.c. No function from this file is used
in the driver code and it is not listed in the Makefile.

Signed-off-by: Michael Straube <straube.linux@gmail.com>
Link: https://lore.kernel.org/r/20190721175735.24173-1-straube.linux@gmail.com


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