Add support for CONFIG_EFI_PARTITION (GUID Partition Table)

The GUID (Globally Unique Identifier) Partition Table (GPT) is a part
of EFI. See http://en.wikipedia.org/wiki/GUID_Partition_Table

Based on linux/fs/partitions/efi.[ch]

Signed-off-by: Richard Retanubun <RichardRetanubun@RugggedCom.com>

README

diff --git a/README b/README
index 36d740f..b10b539 100644
--- a/README
+++ b/README
@@ -687,7 +687,7 @@
 
 - Partition Support:
 		CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
-		and/or CONFIG_ISO_PARTITION
+		and/or CONFIG_ISO_PARTITION and/or CONFIG_EFI_PARTITION
 
 		If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
 		CONFIG_CMD_SCSI) you must configure support for at