lib: Use smbios_bus_width_to_spd_width for setting dimm.bus_width

Make use of `smbios_bus_width_to_spd_width()` for filling DIMM info.

Additionally, ensures dimm_info_util.c file is getting compiled for
romstage.

TEST=dmidecode -t 17 output Total Width and Data Width as expected.

Change-Id: I7fdc19fadc576dec43e12f182fe088707e6654d9
Signed-off-by: Subrata Banik <subrata.banik@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/58655
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>

src/lib/Makefile.inc

@@ -110,6 +110,7 @@ romstage-$(CONFIG_COLLECT_TIMESTAMPS) += timestamp.c
 romstage-$(CONFIG_CONSOLE_CBMEM) += cbmem_console.c
 
 romstage-y += compute_ip_checksum.c
+romstage-y += dimm_info_util.c
 ifeq ($(CONFIG_COMPILER_GCC),y)
 bootblock-$(CONFIG_ARCH_BOOTBLOCK_X86_32) += gcc.c
 verstage-$(CONFIG_ARCH_VERSTAGE_X86_32) += gcc.c