dpaa2-switch: put MAC endpoint device on disconnect

dpaa2-switch: put MAC endpoint device on disconnect

fsl_mc_get_endpoint() returns the MAC endpoint device with a reference
taken through device_find_child(). The switch port connect path stores
that device in mac->mc_dev and keeps it for the lifetime of the connected
MAC object.

However, the disconnect path only closes the MAC and frees the dpaa2_mac
object. It does not drop the endpoint device reference stored in
mac->mc_dev, so every successful connect leaks that device reference when
the MAC is later disconnected.

Drop the endpoint device reference before freeing the dpaa2_mac object.

Fixes: 84cba72956fd ("dpaa2-switch: integrate the MAC endpoint support")
Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20260708111025.749311-1-lgs201920130244@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>