Revert "google/pyro: remove Wacom touchscreen probed flag"

Reason for revert:
Pyro has two touchscreen sources: WACOM/ELAN.
It will not have both touchscreen IC in one system at the same time.

So the "probed" property of WACOM i2c device is mandatory to set for kernel
to know whether it exists before driver initializes it.

Otherwise in ELAN case, when driver fails to init WACOM i2c device, ACPI _OFF
will be invoked to set GPIO#152 low to cut off power.

BUG=chrome-os-partner:62371
BRANCH=reef
TEST=emerge-pyro coreboot
Change-Id: I30f467bd8720d959686dc14f7877e6bc11ea6213
Signed-off-by: Kevin Chiu <Kevin.Chiu@quantatw.com>
Reviewed-on: https://review.coreboot.org/18291
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins)
Reviewed-by: Furquan Shaikh <furquan@google.com>

src/mainboard/google/reef/variants/pyro/devicetree.cb

@@ -187,6 +187,7 @@ chip soc/intel/apollolake
 					 .cid = PNP0C50_CID,
 					 .desc = WCOM_TS_DESC,
 					 .irq = IRQ_LEVEL_LOW(GPIO_21_IRQ),
+					 .probed = 1,
 					 .reset_gpio = ACPI_GPIO_OUTPUT_ACTIVE_HIGH(GPIO_36),
 					 .reset_delay_ms = 20,
 					 .enable_gpio = ACPI_GPIO_OUTPUT_ACTIVE_HIGH(GPIO_152),