configs: zynq-common: Fix mode 2r2t

For AD9364 there is only mode 1r1t available but this condition was
enforced for all compatible devices. This patch fixes the mode option for
AD9361 and AD9363.

Fixes: e1eb71f ("configs: zynq-common: Fix SPI env update")
Signed-off-by: Mircea Caprioru <mircea.caprioru@analog.com>

include/configs/zynq-common.h

@@ -311,7 +311,7 @@
 		"if test -n ${cs_gpio}; then " \
 			"fdt set /amba/axi_quad_spi@7C430000/ cs-gpios \"<0x06 ${cs_gpio} 0>\"; " \
 		"fi; " \
-		"if test -n ${compatible} = ad9364 || test -n ${attr_val} = ad9364; then " \
+		"if test \"${compatible}\" = ad9364 || test \"${attr_val}\" = ad9364; then " \
 			"fdt set /fpga-axi/cf-ad9361-dds-core-lpc@79024000 compatible adi,axi-ad9364-dds-6.00.a; " \
 			"if test ! ${mode} = 1r1t; then " \
 				"fdt rm /amba/spi@e0006000/ad9361-phy@0 adi,2rx-2tx-mode-enable; " \