soc/intel/broadwell: Fix copy-pasted copy-paste error

The code with this error was copy-pasted from Haswell. It was fixed with
commit dab81a4 (northbridge/intel/haswell: Fix copy paste error) for
Haswell. Do the same for Broadwell. Given that LP SKUs only support one
DIMM per channel, this change makes no difference in practice.

Change-Id: I2a7bee617354870aa4334b6c0e6b49d831e64c23
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/46366
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Michael Niewöhner <foss@mniewoehner.de>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>

src/soc/intel/broadwell/romstage/raminit.c

@@ -61,7 +61,7 @@ static void report_memory_config(void)
 
 		printk(BIOS_DEBUG, "   DIMMB %d MB width %s %s rank%s\n",
 		       ((ch_conf >> 8) & 0xff) * 256,
-		       ((ch_conf >> 19) & 1) ? "x16" : "x8 or x32",
+		       ((ch_conf >> 20) & 1) ? "x16" : "x8 or x32",
 		       ((ch_conf >> 18) & 1) ? "dual" : "single",
 		       ((ch_conf >> 16) & 1) ? ", selected" : "");
 	}