mb/google/myst: Enable console UART

Enable the console UART for myst devices.

Bug=b:275900837
TEST=builds

Signed-off-by: Jon Murphy <jpmurphy@google.com>
Change-Id: I52c1b86c46907216d88f98917968b833af0d5d41
Reviewed-on: https://review.coreboot.org/c/coreboot/+/74103
Reviewed-by: Eric Lai <eric_lai@quanta.corp-partner.google.com>
Reviewed-by: Tim Van Patten <timvp@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Karthik Ramasubramanian <kramasub@google.com>
diff --git a/src/mainboard/google/myst/Kconfig b/src/mainboard/google/myst/Kconfig
index 0305e25..353f23c 100644
--- a/src/mainboard/google/myst/Kconfig
+++ b/src/mainboard/google/myst/Kconfig
@@ -7,6 +7,7 @@
 
 config BOARD_SPECIFIC_OPTIONS
 	def_bool y
+	select AMD_SOC_CONSOLE_UART
 	select BOARD_ROMSIZE_KB_16384
 	select EC_GOOGLE_CHROMEEC
 	select EC_GOOGLE_CHROMEEC_ESPI
diff --git a/src/mainboard/google/myst/variants/baseboard/devicetree.cb b/src/mainboard/google/myst/variants/baseboard/devicetree.cb
index ef41b0d..7980101 100644
--- a/src/mainboard/google/myst/variants/baseboard/devicetree.cb
+++ b/src/mainboard/google/myst/variants/baseboard/devicetree.cb
@@ -7,4 +7,5 @@
 			end
 		end
 	end # domain
+	device ref uart_0 on end # UART0
 end	# chip soc/amd/phoenix