dt-bindings: ti_sci_pm_domains: Add support for exclusive and shared access

TISCI protocol supports for enabling the device either with exclusive
permissions for the requesting host or with sharing across the hosts.
There are certain devices which are exclusive to Linux context and
there are certain devices that are shared across different host contexts.
So add support for getting this information from DT by increasing
the power-domain cells to 2.

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
diff --git a/doc/device-tree-bindings/power/ti,sci-pm-domain.txt b/doc/device-tree-bindings/power/ti,sci-pm-domain.txt
index 0e190e2..72d9fbc 100644
--- a/doc/device-tree-bindings/power/ti,sci-pm-domain.txt
+++ b/doc/device-tree-bindings/power/ti,sci-pm-domain.txt
@@ -17,8 +17,15 @@
 Required Properties:
 --------------------
 - compatible: Must be "ti,sci-pm-domain"
-- #power-domain-cells: Must be 1 so that an id can be provided in each
-		       device node.
+- #power-domain-cells: Can be one of the following:
+			1: Containing the device id of each node
+			2: First entry should be device id
+			   Second entry should be one of the floowing:
+			   TI_SCI_PD_EXCLUSIVE: To allow device to be
+						exclusively controlled by
+						the requesting hosts.
+			   TI_SCI_PD_SHARED: To allow device to be shared
+					     by multiple hosts.
 
 Example (AM65x):
 ----------------