powerpc/pseries/iommu: Update remove_dma_window() to accept property name

Update remove_dma_window() so it can be used to remove DDW with a given
property name.

This enables the creation of new property names for DDW, so we can
have different usage for it, like indirect mapping.

Also, add return values to it so we can check if the property was found
while removing the active DDW. This allows skipping the remaining property
names while reducing the impact of multiple property names.

Signed-off-by: Leonardo Bras <leobras.c@gmail.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210817063929.38701-9-leobras.c@gmail.com