staging: vt6656: rf.c additional power.

Provides extra power on weak RSSI.

The values orginate from the vendors driver.

It is applied later in RFbRawSetPower to simplify and check that it doesn't
exceed the max power.

Vendor driver VT6656_Linux_src_v1.21.03_x86_11.04.zip
http://www.viaembedded.com/servlet/downloadSvl?id=1890&download_file_id=14704
This is GPL-licensed code.

vendors code
...
if (pDevice->byRFType == RF_VT3226D0) {
	if (lRSSI == 0){
		lAdditionalPower = 7;
	}
	else if ((lRSSI < -60) && (lRSSI >= -65)){
		lAdditionalPower = 5;
		//lAdditionalPower = 9;
	}
	else if ((lRSSI < -65) && (lRSSI >= -70)){
		lAdditionalPower = 7;
		//lAdditionalPower = 9;
	}
	else if ((lRSSI < -70) && (lRSSI >= -80)){
		lAdditionalPower = 9;
		}
	else if (lRSSI < -80) {
		lAdditionalPower = 9;
	}
}
else {
	if (lRSSI == 0){
		lAdditionalPower = 7;
	}
	else if ((lRSSI < -70) && (lRSSI >= -75)){
		lAdditionalPower = 5;
	}
	else if ((lRSSI < -75) && (lRSSI >= -80)){
			lAdditionalPower = 7;
		}
		else if (lRSSI < -80) {
			lAdditionalPower = 9;
		}
	}

...

Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>