meta-zaius: Use udev dev and fix DEVPATH/PATH

For the checkstop GPIO monitoring configuration, use gpio-keys device
created by udev rule. Also port the DEVPATH fix for the $PATH env being
overridden.

Change-Id: I9ff522b20bdf92f1832dccb9f87664b6104bb5c1
Signed-off-by: Xo Wang <xow@google.com>
diff --git a/meta-zaius/recipes-phosphor/host/checkstop-monitor/obmc/gpio/checkstop b/meta-zaius/recipes-phosphor/host/checkstop-monitor/obmc/gpio/checkstop
index 23cd0a0..a94b241 100644
--- a/meta-zaius/recipes-phosphor/host/checkstop-monitor/obmc/gpio/checkstop
+++ b/meta-zaius/recipes-phosphor/host/checkstop-monitor/obmc/gpio/checkstop
@@ -1,4 +1,4 @@
-PATH=/dev/input/event0
+DEVPATH=/dev/input/by-path/platform-gpio-keys-event
 KEY=47
 POLARITY=1
 TARGET=obmc-host-crash@0.target