dm: Fix CMD_DM enabling

The patch "dm: Change CMD_DM enabling"
(sha1: 08a00cba) was incorrectly updated
and PICO_IMX7D is missing imply CMD_DM and WARP7 has it twice.
This patch is fixing it.

Reviewed-by: Joe Hershberger <joe.hershberger@ni.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>