arm64: zynqmp: Enable ISSI flash for some platforms

Enable ISSI flash for platforms. Xilinx reference boards are also used
internally with different flash part to increase coverage that's why
enable also ISSI parts for all these boards even if that board is
released only with one part.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/configs/xilinx_zynqmp_zc1751_xm015_dc1_defconfig b/configs/xilinx_zynqmp_zc1751_xm015_dc1_defconfig
index 36093e9..f4ece0c 100644
--- a/configs/xilinx_zynqmp_zc1751_xm015_dc1_defconfig
+++ b/configs/xilinx_zynqmp_zc1751_xm015_dc1_defconfig
@@ -63,6 +63,7 @@
 CONFIG_SPI_FLASH=y
 CONFIG_SPI_FLASH_BAR=y
 CONFIG_SF_DUAL_FLASH=y
+CONFIG_SPI_FLASH_ISSI=y
 CONFIG_SPI_FLASH_MACRONIX=y
 CONFIG_SPI_FLASH_SPANSION=y
 CONFIG_SPI_FLASH_STMICRO=y