common: Drop part.h from common header

Move this uncommon header out of the common header.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/include/efi_loader.h b/include/efi_loader.h
index 75c20e4..20f86c3 100644
--- a/include/efi_loader.h
+++ b/include/efi_loader.h
@@ -9,11 +9,14 @@
 #define _EFI_LOADER_H 1
 
 #include <common.h>
+#include <blk.h>
 #include <part_efi.h>
 #include <efi_api.h>
 #include <image.h>
 #include <pe.h>
 
+struct blk_desc;
+
 static inline int guidcmp(const void *g1, const void *g2)
 {
 	return memcmp(g1, g2, sizeof(efi_guid_t));