adi/rc-dff: Add Initial implementaion

* Add ADI vendor

Copy Intel Mohon Peak mainboard to ADI vendor. No functional changes,
only string and ifdef names changed.

Change-Id: I25a6d0ec549c79a8ff149d39f72648f625dc36fe
Signed-off-by: Chris Ching <chingcodes@google.com>
Reviewed-on: https://review.coreboot.org/14778
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>
diff --git a/src/mainboard/adi/Kconfig b/src/mainboard/adi/Kconfig
new file mode 100644
index 0000000..5079d96
--- /dev/null
+++ b/src/mainboard/adi/Kconfig
@@ -0,0 +1,16 @@
+if VENDOR_ADI
+
+choice
+	prompt "Mainboard model"
+
+source "src/mainboard/adi/*/Kconfig.name"
+
+endchoice
+
+source "src/mainboard/adi/*/Kconfig"
+
+config MAINBOARD_VENDOR
+	string
+	default "ADI"
+
+endif # VENDOR_ADI