Add firmware for lgs8g75

This is taken from the lgs8gxx driver as of 2.6.32-rc5.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

WHENCE

@@ -1184,3 +1184,12 @@ Found in hex form in kernel source.
 
 --------------------------------------------------------------------------
 
+Driver: lgs8gxx - Legend Silicon GB20600 demodulator driver
+
+File: lgs8g75.fw
+
+Licence: Unknown
+
+Found in hex form in kernel source.
+
+--------------------------------------------------------------------------