xilinx: zynq: Enable capsule update for Antminer S9

Capsule update helps with easier firmware development that's why enable it
by default to be able to update system without replugging SD card again and
again.

Signed-off-by: Michal Simek <michal.simek@amd.com>
Link: https://lore.kernel.org/r/8f8deb5f46c0f2d4b687b626f4de221873133856.1699866313.git.michal.simek@amd.com