xilinx: mbv: Remove redundancy in MB-V defconfigs

xilinx: mbv: Remove redundancy in MB-V defconfigs

Removes redundant configuration options from MB-V platform defconfigs
targeting both modes. Common settings are now placed in
xilinx_mbv32_defconfig, which is included via the #include <configs/...>.
This approach centralizes configuration management, reduces duplication,
and makes future maintenance easier.

Signed-off-by: Padmarao Begari <padmarao.begari@amd.com>
Signed-off-by: Michal Simek <michal.simek@amd.com>
Link: https://lore.kernel.org/r/585f96d85b656803bd382ac25425d68998f24ed5.1759393175.git.michal.simek@amd.com