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>