xilinx: zynqmp: make spi flash support optional

The set_dfu_alt_info function use the CONFIG_SYS_SPI_U_BOOT_OFFS define
to set the dfu_alt_info environment variable for qspi boot mode. Guard
the usage of CONFIG_SYS_SPI_U_BOOT_OFFS to make spi flash support
optional.

Signed-off-by: Stefan Herbrechtsmeier <stefan.herbrechtsmeier@weidmueller.com>
Link: https://lore.kernel.org/r/20220620163650.18756-11-stefan.herbrechtsmeier-oss@weidmueller.com
Signed-off-by: Michal Simek <michal.simek@amd.com>
diff --git a/board/xilinx/zynqmp/zynqmp.c b/board/xilinx/zynqmp/zynqmp.c
index 06f6dba..106c395 100644
--- a/board/xilinx/zynqmp/zynqmp.c
+++ b/board/xilinx/zynqmp/zynqmp.c
@@ -667,6 +667,7 @@
 				 bootseq, multiboot, bootseq,
 				 CONFIG_SPL_FS_LOAD_PAYLOAD_NAME, bootseq);
 		break;
+#if defined(CONFIG_SYS_SPI_U_BOOT_OFFS)
 	case QSPI_MODE_24BIT:
 	case QSPI_MODE_32BIT:
 		snprintf(buf, DFU_ALT_BUF_LEN,
@@ -675,6 +676,7 @@
 			 multiboot * SZ_32K, CONFIG_SPL_FS_LOAD_PAYLOAD_NAME,
 			 CONFIG_SYS_SPI_U_BOOT_OFFS);
 		break;
+#endif
 	default:
 		return;
 	}