Kconfig: Add a new DISTRO_DEFAULTS Kconfig option

DISTRO_DEFAULTS is intended to mirror / replace
include/config_distro_defaults.h.

The intend is for boards which include this file to select this from
their Kconfig files and when moving setting to Kconfig which are #define-ed
in config_distro_defaults.h to select this from DISTRO_DEFAULTS so that
boards which have selected DISTRO_DEFAULTS will keep the same configuration
as before without needing any defconfig file changes.

The initial list of selected things matches all settings recently removed
from config_distro_defaults.h because they have been converted to Kconfig,
with the exception of CMD_ELF and CMD_NET, which have a default of y, if
the default of these ever changes they should be selected by DISTRO_DEFAULTS
too.

For testing and example purposes this commit also converts ARCH_SUNXI
to use DISTRO_DEFAULT instead of selecting everything it needs itself.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/doc/README.distro b/doc/README.distro
index e1b7216..77d5c6d 100644
--- a/doc/README.distro
+++ b/doc/README.distro
@@ -162,6 +162,12 @@ U-Boot Implementation
 Enabling the distro options
 ---------------------------
 
+In your board's defconfig, enable the DISTRO_DEFAULTS option by adding
+a line with "CONFIG_DISTRO_DEFAULTS=y". If you want to enable this
+from Kconfig itself, for e.g. all boards using a specific SoC then
+add a "default y if ARCH_FOO" to the DISTRO_DEFAULTS section of
+the Kconfig file in the root of the u-boot sources.
+
 In your board configuration file, include the following:
 
 ------------------------------------------------------------