soc/intel/cannonlake: Configure common FSP memory settings only once

`meminit_memcfg()` does common memory configuration, which is not
specific to each DIMM. Thus, move it out of the for-loop and call it
once.

Change-Id: If74875b45cd0d7a759883eaf564505ebf281bed5
Signed-off-by: Felix Singer <felixsinger@posteo.net>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/60058
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Paul Menzel <paulepanter@mailbox.org>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

src/soc/intel/cannonlake/cnl_memcfg_init.c

@@ -136,7 +136,7 @@ void cannonlake_memcfg_init(FSP_M_CONFIG *mem_cfg,
 		default:
 			die("no valid way to read mem info");
 		}
+	}
 
 	meminit_memcfg(mem_cfg, cnl_cfg);
-	}
 }