staging: rtl8188eu: Remove function rtw_hal_sreset_reset()

rtw_hal_sreset_reset() is a wrapper to call
rtl8188e_silentreset_for_specific_platform(), which has empty defination.

Signed-off-by: navin patidar <navin.patidar@gmail.com>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>