configs/zynqmp_zcu106_defconfig: move to board rev1.0

configs/zynqmp_zcu106_defconfig: move to board rev1.0

Migrate the zynqmp_zcu106_defconfig to rev1.0 ddr memory, since all new boards
will be using the rev1.0 ddr memory.

This patch also adds documentation in the board/zynqmp/readme.txt explaining
the issue related to the change in ddr memory.  Should users not see anything
printing from the board during boot, the most likely issue is that the board
has the original ddr memory and the u-boot device tree needs to be configured
accordingly to revA.

Original DDR Memory:
BR2_TARGET_UBOOT_CUSTOM_MAKEOPTS="DEVICE_TREE=zynqmp-zcu106-revA"

More information regarding this issue can be found here:
https://support.xilinx.com/s/article/71961?language=en_US

Signed-off-by: Neal Frager <[email protected]>
Reviewed-by: Brandon Maier <[email protected]>
Signed-off-by: Thomas Petazzoni <[email protected]>