Alter Channel 2 Logarithmic Input dBm scale and range.

The scale of -45 to 5 dBm with a range of 50 dBm has been altered
and is now -50 to 10dBm with a range of 60 dBm in line with the
findings by Eduardo Alonso <ea3ghs@gmail.com>.

Signed-off-by: Gray Remlin <gryrmln@gmail.com>