dt-bindings: Add devicetree bindings

Add snapshot of device tree bindings from keystone common kernel, branch
"android-mainline-keystone-qcom-release" at c4c12103f9c0 ("Snap for 9228065
from e32903b9a63bb558df8b803b076619c53c16baad to
android-mainline-keystone-qcom-release").

Change-Id: I7682079615cbd9f29340a5c1f2a1d84ec441a1f1
Signed-off-by: Melody Olvera <quic_molvera@quicinc.com>

bindings/powerpc/opal/sensor-groups.txt

@@ -0,0 +1,27 @@
+IBM OPAL Sensor Groups Binding
+-------------------------------
+
+Node: /ibm,opal/sensor-groups
+
+Description: Contains sensor groups available in the Powernv P9
+servers. Each child node indicates a sensor group.
+
+- compatible : Should be "ibm,opal-sensor-group"
+
+Each child node contains below properties:
+
+- type : String to indicate the type of sensor-group
+
+- sensor-group-id: Abstract unique identifier provided by firmware of
+		   type <u32> which is used for sensor-group
+		   operations like clearing the min/max history of all
+		   sensors belonging to the group.
+
+- ibm,chip-id : Chip ID
+
+- sensors : Phandle array of child nodes of /ibm,opal/sensor/
+	    belonging to this group
+
+- ops : Array of opal-call numbers indicating available operations on
+	sensor groups like clearing min/max, enabling/disabling sensor
+	group.