net: zynq_gem: reinitialize RX BDs on every init

net: zynq_gem: reinitialize RX BDs on every init

Reinitialize RX BDs and rewrite rxqbase on every init instead of only
on the first init. This ensures a clean BD state on every init for all
GEM configurations.
For AMD Versal Gen 2 10GBE this is required since the USX block
resets the RX DMA pointer to rxqbase on each init, so BDs must be
rebuilt each time to stay in sync with hardware.

Signed-off-by: Pranav Tilak <pranav.vinaytilak@amd.com>
Signed-off-by: Michal Simek <michal.simek@amd.com>
Link: https://lore.kernel.org/r/20260410093018.1461732-4-pranav.vinaytilak@amd.com