fit: make sha256 support optional

sha256 has some beefy memory footprint.
Make it optional for constrained systems.

Signed-off-by: Dirk Eibach <dirk.eibach@gdsys.cc>

README

@@ -3269,6 +3269,11 @@ FIT uImage format:
 		disabled. If a board need legacy image format support
 		enable this through CONFIG_IMAGE_FORMAT_LEGACY
 
+		CONFIG_FIT_DISABLE_SHA256
+		Supporting SHA256 hashes has quite an impact on binary size.
+		For constrained systems sha256 hash support can be disabled
+		with this option.
+
 - Standalone program support:
 		CONFIG_STANDALONE_LOAD_ADDR
 

include/configs/dlvision-10g.h

@@ -40,6 +40,7 @@
 /* new uImage format support */
 #define CONFIG_FIT
 #define CONFIG_FIT_VERBOSE	/* enable fit_format_{error,warning}() */
+#define CONFIG_FIT_DISABLE_SHA256
 
 #define CONFIG_ENV_IS_IN_FLASH	/* use FLASH for environment vars */
 

include/configs/io.h

@@ -40,6 +40,7 @@
 /* new uImage format support */
 #define CONFIG_FIT
 #define CONFIG_FIT_VERBOSE	/* enable fit_format_{error,warning}() */
+#define CONFIG_FIT_DISABLE_SHA256
 
 #define CONFIG_ENV_IS_IN_FLASH	/* use FLASH for environment vars */
 

include/configs/iocon.h

@@ -39,6 +39,7 @@
 /* new uImage format support */
 #define CONFIG_FIT
 #define CONFIG_FIT_VERBOSE	/* enable fit_format_{error,warning}() */
+#define CONFIG_FIT_DISABLE_SHA256
 
 #define CONFIG_ENV_IS_IN_FLASH	/* use FLASH for environment vars */
 

include/configs/neo.h

@@ -37,6 +37,7 @@
 /* new uImage format support */
 #define CONFIG_FIT
 #define CONFIG_FIT_VERBOSE	/* enable fit_format_{error,warning}() */
+#define CONFIG_FIT_DISABLE_SHA256
 
 #define CONFIG_ENV_IS_IN_FLASH	/* use FLASH for environment vars */
 

include/image.h

@@ -72,6 +72,11 @@ struct lmb;
 #  define IMAGE_ENABLE_SHA256	1
 # endif
 
+#ifdef CONFIG_FIT_DISABLE_SHA256
+#undef CONFIG_SHA256
+#undef IMAGE_ENABLE_SHA256
+#endif
+
 #ifndef IMAGE_ENABLE_CRC32
 #define IMAGE_ENABLE_CRC32	0
 #endif