xilinx: versal-net: Disable LMB for mini configuration

There is no reason to have LMB enabled on mini configuration because it is
only consuming space that's why disable it.

Signed-off-by: Michal Simek <michal.simek@amd.com>
Link: https://lore.kernel.org/r/47067c87b6b2e7600d3c2808e7d0aa6fe82aa1fe.1668612795.git.michal.simek@amd.com