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/avnet_ultra96_rev1_defconfig b/configs/avnet_ultra96_rev1_defconfig
index 12b49da..7738973 100644
--- a/configs/avnet_ultra96_rev1_defconfig
+++ b/configs/avnet_ultra96_rev1_defconfig
@@ -59,6 +59,7 @@
 CONFIG_MMC_SDHCI_ZYNQ=y
 CONFIG_SPI_FLASH=y
 CONFIG_SPI_FLASH_BAR=y
+CONFIG_SPI_FLASH_ISSI=y
 CONFIG_SPI_FLASH_MACRONIX=y
 CONFIG_SPI_FLASH_SPANSION=y
 CONFIG_SPI_FLASH_STMICRO=y