post: Migrate to Kconfig

We move the existing CONFIG_POST_* functionality over to CFG_POST and
then introduce CONFIG_POST to Kconfig.

Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/configs/pg_wcom_seli8_update_defconfig b/configs/pg_wcom_seli8_update_defconfig
index 01a6198..d6f4a05 100644
--- a/configs/pg_wcom_seli8_update_defconfig
+++ b/configs/pg_wcom_seli8_update_defconfig
@@ -98,3 +98,4 @@
 CONFIG_SPECIFY_CONSOLE_INDEX=y
 CONFIG_DM_SERIAL=y
 CONFIG_SYS_NS16550=y
+CONFIG_POST=y