firmware: Update Kconfig help text for Google firmware

The help text for GOOGLE_FIRMWARE states that it should only be
enabled when building a kernel for Google's own servers.  However,
many of the drivers dependent on it are also useful on Chromebooks or
on any platform using coreboot.

Update the help text to reflect this double duty.

Fixes: d384d6f4 ("firmware: google memconsole: Add coreboot support")
Reviewed-by: NJulius Werner <jwerner@chromium.org>
Signed-off-by: NBen Hutchings <ben@decadent.org.uk>
Link: https://lore.kernel.org/r/20180618225540.GD14131@decadent.org.ukSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/firmware/google/Kconfig

@@ -3,9 +3,9 @@ menuconfig GOOGLE_FIRMWARE
 	bool "Google Firmware Drivers"
 	default n
 	help
-	  These firmware drivers are used by Google's servers.  They are
-	  only useful if you are working directly on one of their
-	  proprietary servers.  If in doubt, say "N".
+	  These firmware drivers are used by Google servers,
+	  Chromebooks and other devices using coreboot firmware.
+	  If in doubt, say "N".
 
 if GOOGLE_FIRMWARE