nb/intel/i440bx: Clear memory errors before ending raminit

i440BX datasheet says all memory errors reported during RAM init
should be ignored. Do as it says.

Change-Id: Iaf85fde813aa083ae62218a2df5aec303e3c9f8c
Signed-off-by: Keith Hui <buurin@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/73952
Reviewed-by: Paul Menzel <paulepanter@mailbox.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/northbridge/intel/i440bx/raminit.c

@@ -1012,5 +1012,10 @@ void sdram_initialize(int s3resume)
 	sdram_set_spd_registers();
 	sdram_enable();
 
+	/* Clear any errors reported during raminit. */
+	pci_write_config32(NB, EAP, 0x3);
+	pci_write_config8(NB, ERRSTS, 0x11);
+	pci_write_config8(NB, ERRSTS + 1, 0x1f);
+
 	timestamp_add_now(TS_INITRAM_END);
 }