arm64: zynqmp: Fix level of gpio reset for usb on kv260 boards

Active level is low that's why it should be fixed.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Link: https://lore.kernel.org/r/86b3a96ce990b0ee0adab221146b5a5c751bd4a9.1645629459.git.michal.simek@xilinx.com