staging: rtl8723au: Use correct register names to set parameters to reduce 80M spur

Use the correct register names when setting parameters to reduce 80M
spur. In addition apply updated 80M spur reduction parameters.

Original patch supplied by Andrew Chang <andrew.chang@realtek.com>

Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>