zynq: Enable CONFIG_ZYNQ_SPI

Tested spi on zynq board with sst flash by enabling
CONFIG_ZYNQ_SPI.

sf probe 1:1 0 0
SF: Detected SST25WF080 with page size 4 KiB, total 1 MiB

Signed-off-by: Jagannadha Sutradharudu Teki <jaganna@xilinx.com>
Acked-by: Siva Durga Prasad Paladugu <sivadur@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

include/configs/zynq.h

@@ -72,6 +72,15 @@
 # define CONFIG_CPU_V6 /* Required by CONFIG_ARM_DCC */
 #endif
 
+#define CONFIG_ZYNQ_SPI
+
+/* SPI */
+#ifdef CONFIG_ZYNQ_SPI
+# define CONFIG_SPI_FLASH
+# define CONFIG_SPI_FLASH_SST
+# define CONFIG_CMD_SF
+#endif
+
 /* Enable the PL to be downloaded */
 #define CONFIG_FPGA
 #define CONFIG_FPGA_XILINX