docs: Fix expected strings for NXP imx8*

Signed-off-by: Guido Günther <guido.gunther@puri.sm>

Documentation/devicetree/bindings/display/imx/dsi_nwl.txt

@@ -10,6 +10,7 @@ Required properties:
 	The following strings are expected:
 			"fsl,imx8qm-mipi-dsi"
 			"fsl,imx8qxp-mipi-dsi"
+			"fsl,imx8mq-mipi-dsi_drm"
 - reg: 			the register range of the MIPI-DSI controller
 - interrupts: 		the interrupt number for this module
 - clock, clock-names: 	phandles to the MIPI-DSI clocks

Documentation/devicetree/bindings/phy/mixel,mipi-dsi-phy.txt

@@ -6,6 +6,10 @@ signals for DSI.
 
 Required properties:
 - compatible: 		"mixel,<soc>-mipi-dsi-phy"
+   The following strings are expected:
+			"mixel,imx8qm-mipi-dsi-phy"
+			"mixel,imx8qxp-mipi-dsi-phy"
+			"mixel,imx8mq-mipi-dsi-phy"
 - reg:			the register range of the PHY controller
 - #phy-cells:		number of cells in PHY, as defined in
 			Documentation/devicetree/bindings/phy/phy-bindings.txt