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/rcc-dff/Kconfig.name b/src/mainboard/adi/rcc-dff/Kconfig.name
new file mode 100644
index 0000000..13d3eb7
--- /dev/null
+++ b/src/mainboard/adi/rcc-dff/Kconfig.name
@@ -0,0 +1,2 @@
+config BOARD_ADI_RCC_DFF
+	bool "ADI RCC-DFF"