cnss2: Notify MHI to use already allocated images

For firmware and RDDM images, notify MHI driver not to free them after
successful allocation. This can help avoid future memory allocation
failure.

Change-Id: Ic19d42c6d56707200099969e36da91f4afed0163
Signed-off-by: Yue Ma <yuem@codeaurora.org>