xilinx: Introduce XILINX_MINI configuration

xilinx: Introduce XILINX_MINI configuration

There is no common symbol which mini configurations are using and recent
get_mem_top() changes adding 1.3kB without having a way to remove it.
That's why introduce new symbol which can be used for removing features
which are not requested by these configurations.

Signed-off-by: Michal Simek <michal.simek@amd.com>
Link: https://lore.kernel.org/r/aa27b72e17057fa8cbdd92a2bbb863a31c8c1226.1731681053.git.michal.simek@amd.com