nb/intel/x4x: Correct and use macros for CLKCFG

The `CLKCFG_UPDATE` macro is copied from gm45 and unused. Correct it and
use the CLKCFG macros instead of magic values.

Tested with BUILD_TIMELESS=1, Asus P5QL PRO remains identical.

Change-Id: I17e972eba21282ac84c7afe10b7149cd1131fd07
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/51877
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/northbridge/intel/x4x/raminit_ddr23.c b/src/northbridge/intel/x4x/raminit_ddr23.c
index 84dbff5..6863ef8 100644
--- a/src/northbridge/intel/x4x/raminit_ddr23.c
+++ b/src/northbridge/intel/x4x/raminit_ddr23.c
@@ -1952,11 +1952,12 @@
 			MCHBAR8_OR(0x1a8, 0x4);
 
 		/* Set frequency */
-		MCHBAR32_AND_OR(0xc00, ~0x70,
-			(s->selected_timings.mem_clk << 4) | (1 << 10));
+		MCHBAR32_AND_OR(CLKCFG_MCHBAR, ~CLKCFG_MEMCLK_MASK,
+			(s->selected_timings.mem_clk << CLKCFG_MEMCLK_SHIFT) | CLKCFG_UPDATE);
 
 		/* Overwrite value if chipset rejects it */
-		s->selected_timings.mem_clk = (MCHBAR8(0xc00) & 0x70) >> 4;
+		s->selected_timings.mem_clk =
+			(MCHBAR8(CLKCFG_MCHBAR) & CLKCFG_MEMCLK_MASK) >> CLKCFG_MEMCLK_SHIFT;
 		if (s->selected_timings.mem_clk > (s->max_fsb + 3))
 			die("Error: DDR is faster than FSB, halt\n");
 	}