MLK-25283-1 dt-binding: imx6q-pcie: add the l1sub for imx8m pcie

Add one clkreq reset to support the L1sub for i.MX8M PCIe.

Signed-off-by: Richard Zhu <[email protected]>
Reviewed-by: Jun Li <[email protected]>
(cherry picked from commit 3ac7bf70f9cda0f25b8d94678e5bbbd70c387b2f)

Author: Richard Zhu

Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt

@@ -83,6 +83,11 @@ Additional required properties for imx8mq-pcie:
 - clock-names: Must include the following additional entries:
 	- "pcie_aux"
 
+Additional required properties to enable L1sub for imx8mq-pcie, imx8mm-pcie
+and imx8mp-pcie:
+- reset-names: Must contain the following entries:
+	       - "clkreq"
+
 Additional required properties for imx8 pcie:
 - hsio-cfg: hsio configration mode when the pcie node is supported.
   mode 1: pciea 2 lanes and one sata ahci port.