u-boot-xlinx: Workaround to trigger network based jtagboot

Currently the jtagboot cmd fails when jtagmemboot failed. This is
because the jtagmemboot returns false when it fail the itest.w or the
booti failed. Thus the network based jtagboot cmd never gets triggered.

The jtagboot can't be purely base on the itest.w because sometimes
the dhcp command triggers the Image download which has valid image
in the ram. This passes the itest.w and iminfo test but fail the
booti.

This patch triggers the network based jtagboot cmd if jtagmemboot
failed.

Signed-off-by: Jason Wu <jason.hy.wu@gmail.com>
Signed-off-by: Nathan Rossi <nathan@nathanrossi.com>

recipes-bsp/u-boot/u-boot-xlnx/arm-zynqmp-xilinx_zynqmp.h-Auto-boot-in-JTAG-if-imag.patch

@@ -28,7 +28,7 @@ index 4714b3317d..0441f3f24f 100644
 -	"jtagboot=tftpboot 80000 Image && tftpboot $fdt_addr system.dtb && " \
 -		 "tftpboot 6000000 rootfs.cpio.ub && booti 80000 6000000 $fdt_addr\0" \
 +	"jtagmemboot=if itest.w *0x80038 == 0x644d5241; then if iminfo 0x6000000; then booti 0x80000 0x6000000 $fdt_addr; else booti 0x80000 - $fdt_addr; fi; fi\0" \
-+	"jtagboot=run jtagmemboot && " \
++	"jtagboot=run jtagmemboot || " \
 +		"tftpboot 80000 Image && tftpboot $fdt_addr system.dtb && " \
 +		"tftpboot 6000000 rootfs.cpio.ub && booti 80000 6000000 $fdt_addr\0" \
  	"nosmp=setenv bootargs $bootargs maxcpus=1\0" \