mb/google/guybrush: Indicate the presence of ACP DMIC

In order to enable ACP DMIC hardware runtime detection, indicate that
ACP DMIC is present.

BUG=b:182960979
TEST=Build and boot to OS in guybrush. Ensure that the _WOV ACPI method
is populated in the ACP device.

Change-Id: I9a53d158ed08a6b46c29bcb8fe3a2a0d108bd6cd
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/55030
Reviewed-by: Furquan Shaikh <furquan@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/mainboard/google/guybrush/variants/baseboard/devicetree.cb

@@ -5,6 +5,7 @@ chip soc/amd/cezanne
 		.acp_pin_cfg = I2S_PINS_I2S_TDM,
 		.acp_i2s_wake_enable = 0,
 		.acp_pme_enable = 0,
+		.dmic_present = 1,
 	}"
 
 	# eSPI Configuration