xilinx: zynqmp: Save bootseq number for SD/EMMC boot modes

For systems which has both sdhci controllers enable it is worth to export
bootseq number for variables. Then the variable can be used in custom
scripts to tune logic for OS.
Signed-off-by: NMichal Simek <michal.simek@xilinx.com>

board/xilinx/zynqmp/zynqmp.c

@@ -648,6 +648,7 @@ int board_late_init(void)
 	if (bootseq >= 0) {
 		bootseq_len = snprintf(NULL, 0, "%i", bootseq);
 		debug("Bootseq len: %x\n", bootseq_len);
+		env_set_hex("bootseq", bootseq);
 	}
 
 	/*