staging: rtl8723bs: Remove some unused functions, macros, and structs

Remove some functions, macros, and structs that have not been used since
they were introduced in commit 554c0a3a ("staging: Add rtl8723bs
sdio wifi driver").

Signed-off-by: 谢致邦 (XIE Zhibang) <Yeking@Red54.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/tencent_C69BFF8D3EC7B66BFCF0063ED3DEF4BC590A@qq.com


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