Kconfig: Move CONFIG_SPL_..._SUPPORT to Kconfig

This series moves all the CONFIG_SPL_..._SUPPORT options to Kconfig and fixes up existing boards to continue to build.

It also adds a few small but useful features to moveconfig.

There is existing work going on in this area, so some of these patches may be superseded. It has taken me a while to get this building cleanly. But I have run out of time so want to get this out.

As mentioned on a recent thread [1] there is some confusion about whether an option means enabling driver support or media support. Andrew's recent series seems like a good vehicle to tidy that up. But I hope this series will make it easier.

There are a few strange features of this conversion. The main difficulty is that some PowerPC boards do things like this in their board config file:

  #ifdef CONFIG_TPL_BUILD
  #define CONFIG_SPL_SERIAL_SUPPORT
  #define CONFIG_SPL_ENV_SUPPORT
  #else
  #define CONFIG_SPL_SERIAL_SUPPORT
  #endif

This means that TPL reuses the SPL options. We can't support this in Kconfig so I have added a small number of CONFIG_TPL_xxx_SUPPORT options to cope with this. This made the conversion more painful than it should have been.

A related issue is boards using a common header file and setting options only for SPL:

  #ifdef CONFIG_SPL_BUILD
  #define CONFIG_SPL_SERIAL_SUPPORT
  #endif

This is not noticed by moveconfig so we have to clean it up manually. Also there are a few incorrect things where Kconfig options are set with #define:

  #ifdef CONFIG_SPL_BUILD
  #define CONFIG_SPL_DM
  #endif

Finally, many defconfig files are not ordered correctly, resulting in larger patches than we might like. It would be great to have a solution for this, perhaps with buildman providing a warning. But it might slow down development.

The series is fully build-tested (for bisectability) and causes no failures for the boards that already pass. The following boards fail for me at present on mainline (which I have not yet looked at):