feat(partition): cleanup partition and gpt headers

The EFI_NAMELEN macro has been moved to efi.h header. Get the macro
from efi.h. Use the struct efi_guid structure for declaring GUID
members in gpt.h

Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
Change-Id: I1c3a2605b9f857b9cf2dcfdaed4dc9d0a2cbf0f0
diff --git a/include/drivers/partition/partition.h b/include/drivers/partition/partition.h
index 5f64833..3ec6fa3 100644
--- a/include/drivers/partition/partition.h
+++ b/include/drivers/partition/partition.h
@@ -10,6 +10,7 @@
 #include <stdint.h>
 
 #include <lib/cassert.h>
+#include <drivers/partition/efi.h>
 
 #if !PLAT_PARTITION_MAX_ENTRIES
 # define PLAT_PARTITION_MAX_ENTRIES	128
@@ -27,8 +28,6 @@
 
 #define LEGACY_PARTITION_BLOCK_SIZE	512
 
-#define EFI_NAMELEN			36
-
 typedef struct partition_entry {
 	uint64_t		start;
 	uint64_t		length;