sb/intel/i82801gx: Add common LPC decode code

Generic LPC decode ranges can now be set from the devicetree.

Change-Id: I1065ec770ad3a743286859efa39dca09ccb733a1
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/36700
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>
Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
diff --git a/src/mainboard/gigabyte/ga-g41m-es2l/devicetree.cb b/src/mainboard/gigabyte/ga-g41m-es2l/devicetree.cb
index 7045dbf..13da3e8 100644
--- a/src/mainboard/gigabyte/ga-g41m-es2l/devicetree.cb
+++ b/src/mainboard/gigabyte/ga-g41m-es2l/devicetree.cb
@@ -50,6 +50,8 @@
       register "sata_ports_implemented" = "0x3"
       register "gpe0_en" = "0x40"
 
+      register "gen2_dec" = "0x007c0291" # HWM
+
       device pci 1b.0 on		# Audio
         subsystemid 0x1458 0xa002
       end