spi: Add support for mspi on brcmstb SoCs

Added documentation for compatibility for brcmstb SoCs :
7425, 7429, 7435, 7216, 7278
Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>
Link: https://lore.kernel.org/r/20200420190853.45614-3-kdasu.kdev@gmail.comSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/spi/brcm,spi-bcm-qspi.txt

@@ -26,6 +26,16 @@ Required properties:
     "brcm,spi-bcm-qspi", "brcm,spi-brcmstb-qspi" : MSPI+BSPI on BRCMSTB SoCs
     "brcm,spi-bcm-qspi", "brcm,spi-brcmstb-mspi" : Second Instance of MSPI
 						   BRCMSTB  SoCs
+    "brcm,spi-bcm7425-qspi", "brcm,spi-bcm-qspi", "brcm,spi-brcmstb-mspi" : Second Instance of MSPI
+    			     			  			    BRCMSTB  SoCs
+    "brcm,spi-bcm7429-qspi", "brcm,spi-bcm-qspi", "brcm,spi-brcmstb-mspi" : Second Instance of MSPI
+    			     			  			    BRCMSTB  SoCs
+    "brcm,spi-bcm7435-qspi", "brcm,spi-bcm-qspi", "brcm,spi-brcmstb-mspi" : Second Instance of MSPI
+    			     			  			    BRCMSTB  SoCs
+    "brcm,spi-bcm7216-qspi", "brcm,spi-bcm-qspi", "brcm,spi-brcmstb-mspi" : Second Instance of MSPI
+    			     			  			    BRCMSTB  SoCs
+    "brcm,spi-bcm7278-qspi", "brcm,spi-bcm-qspi", "brcm,spi-brcmstb-mspi" : Second Instance of MSPI
+    			     			  			    BRCMSTB  SoCs
     "brcm,spi-bcm-qspi", "brcm,spi-nsp-qspi"     : MSPI+BSPI on Cygnus, NSP
     "brcm,spi-bcm-qspi", "brcm,spi-ns2-qspi"     : NS2 SoCs