mb/google/volteer/var/elemi: Configure IRQ as level triggered for elan_ts

Follow elan's suggestion to configure IRQ as level trigger to prevent touchscreen lost

BUG=b:180778934
BRANCH=firmware-volteer-13672.B
TEST=emerge-volteer coreboot

Signed-off-by: Wisley Chen <wisley.chen@quantatw.com>
Change-Id: I3aca0ad20791c989dec9e70d69d637b28c9cc043
Reviewed-on: https://review.coreboot.org/c/coreboot/+/50417
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/mainboard/google/volteer/variants/elemi/overridetree.cb b/src/mainboard/google/volteer/variants/elemi/overridetree.cb
index 2c36bc9..5aba269 100644
--- a/src/mainboard/google/volteer/variants/elemi/overridetree.cb
+++ b/src/mainboard/google/volteer/variants/elemi/overridetree.cb
@@ -239,7 +239,7 @@
 			chip drivers/i2c/generic
 				register "hid" = ""ELAN0001""
 				register "desc" = ""ELAN Touchscreen""
-				register "irq" = "ACPI_IRQ_EDGE_LOW(GPP_E7_IRQ)"
+				register "irq" = "ACPI_IRQ_LEVEL_LOW(GPP_E7_IRQ)"
 				register "probed" = "1"
 				register "reset_gpio" =
 							"ACPI_GPIO_OUTPUT_ACTIVE_LOW(GPP_C10)"