Make CBFS output more consistent

- Prefix all CBFS output messages with CBFS:
- Add an option DEBUG_CBFS that is off by default. Without DEBUG_CBFS
  enabled, the code will no longer print all the files it walks for
  every file lookup.
- Add DEBUG() macro next to LOG() and ERROR() to specify which messages
  should only be visible with DEBUG_CBFS printed.
- Actually print a message when the file we're looking for was found. :)

old:
Searching for fallback/coreboot_ram
Check cmos_layout.bin
Check pci8086,0106.rom
Check fallback/romstage
Check fallback/coreboot_ram

Change-Id: I2d731fae17a5f6ca51d435cfb7a58d6e017efa24
Stage: loading fallback/coreboot_ram @ 0x100000 (540672 bytes), entry @ 0x100000
Stage: done loading.
new:
CBFS: Looking for 'fallback/coreboot_ram'
CBFS: found.
CBFS: loading stage fallback/coreboot_ram @ 0x100000 (507904 bytes), entry @ 0x100000
CBFS: stage loaded.
Signed-off-by: Stefan Reinauer <reinauer@google.com>
Reviewed-on: http://review.coreboot.org/993
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

src/lib/cbfs_core.c

@@ -40,6 +40,9 @@
  *      print an error message x (in printf format)
  *
  * LOG(x...)
+ *      print a message x (in printf format)
+ *
+ * DEBUG(x...)
  *      print a debug message x (in printf format)
  *
  * romstart()
@@ -86,7 +89,7 @@ struct cbfs_file *cbfs_find(const char *name)
 	struct cbfs_header *header = get_cbfs_header();
 	if (header == (void*)0xffffffff) return NULL;
 
-	LOG("Searching for %s\n", name);
+	LOG("Looking for '%s'\n", name);
 
 	void *data, *dataend, *origdata;
 	/* find first entry */
@@ -111,8 +114,9 @@ struct cbfs_file *cbfs_find(const char *name)
 			data = phys_to_virt(CBFS_ALIGN_UP(virt_to_phys(data), align));
 			continue;
 		}
-		LOG("Check %s\n", CBFS_NAME(file));
+		DEBUG("Check '%s'\n", CBFS_NAME(file));
 		if (strcmp(CBFS_NAME(file), name) == 0) {
+			LOG("found.\n");
 			return file;
 		}
 		void *olddata = data;