arm: socfpga: dts: socrates: Add spi1/2 aliases needed DM SPI probing

Without this alias, DM based probing does not work. So lets add this
alias to get the bus numbering correct for the Designware SPI
controllers.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Chin Liang See <clsee@altera.com>
Cc: Dinh Nguyen <dinguyen@altera.com>
Cc: Vince Bridgers <vbridger@altera.com>
Cc: Marek Vasut <marex@denx.de>
Acked-by: Pavel Machek <pavel@denx.de>

arch/arm/dts/socfpga_cyclone5_socrates.dts

@@ -16,6 +16,8 @@
 
  	aliases {
 		spi0 = "/spi@ff705000";		/* QSPI */
+		spi1 = "/spi@fff00000";
+		spi2 = "/spi@fff01000";
  	};
 
 	memory {