Kconfig: Move CONFIG_FIT and related options to Kconfig

There are already two FIT options in Kconfig but the CONFIG options are
still in the header files. We need to do a proper move to fix this.

Move these options to Kconfig and tidy up board configuration:

   CONFIG_FIT
   CONFIG_OF_BOARD_SETUP
   CONFIG_OF_SYSTEM_SETUP
   CONFIG_FIT_SIGNATURE
   CONFIG_FIT_BEST_MATCH
   CONFIG_FIT_VERBOSE
   CONFIG_OF_STDOUT_VIA_ALIAS
   CONFIG_RSA

Unfortunately the first one is a little complicated. We need to make sure
this option is not enabled in SPL by this change. Also this option is
enabled automatically in the host builds by defining CONFIG_FIT in the
image.h file. To solve this, add a new IMAGE_USE_FIT #define which can
be used in files that are built on the host but must also build for U-Boot
and SPL.

Note: Masahiro's moveconfig.py script is amazing.

Signed-off-by: Simon Glass <sjg@chromium.org>
[trini: Add microblaze change, various configs/ re-applies]
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/rpi_2_defconfig b/configs/rpi_2_defconfig
index b80ac16..ff515fd 100644
--- a/configs/rpi_2_defconfig
+++ b/configs/rpi_2_defconfig
@@ -1,6 +1,7 @@
 CONFIG_ARM=y
 CONFIG_ARCH_BCM283X=y
 CONFIG_TARGET_RPI_2=y
+CONFIG_OF_BOARD_SETUP=y
 CONFIG_SYS_PROMPT="U-Boot> "
 # CONFIG_CMD_IMLS is not set
 # CONFIG_CMD_FLASH is not set