{bd82x6x,i82801gx,ibexpeak,lynxpoint}: Remove dead code and use macro

Use BIOS_CNTL defined macro instead of magic number.

Change-Id: I0d2b555ada9c2893af4f85422128f5a8b04e2fc6
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/29990
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Rudolph <siro@das-labor.org>
diff --git a/src/southbridge/intel/bd82x6x/lpc.c b/src/southbridge/intel/bd82x6x/lpc.c
index f7bb7e4..7737501 100644
--- a/src/southbridge/intel/bd82x6x/lpc.c
+++ b/src/southbridge/intel/bd82x6x/lpc.c
@@ -436,9 +436,9 @@
 	u8 reg8;
 
 	printk(BIOS_SPEW, "Enabling BIOS updates outside of SMM... ");
-	reg8 = pci_read_config8(dev, 0xdc);	/* BIOS_CNTL */
+	reg8 = pci_read_config8(dev, BIOS_CNTL);
 	reg8 &= ~(1 << 5);
-	pci_write_config8(dev, 0xdc, reg8);
+	pci_write_config8(dev, BIOS_CNTL, reg8);
 }
 
 static void pch_fixups(struct device *dev)