bus: fsl-mc: add the dprc_get_mem() command to the whitelist

Add a new MC command to the list of accepted firmware commands.
The DPRC_GET_MEM command can be used to gather information on the
internal memory characteristics.

Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Link: https://lore.kernel.org/r/20250408105814.2837951-5-ioana.ciornei@nxp.com


Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>