Revert "remoteproc: Merge table_ptr and cached_table pointers"

Following any fw_rsc_vdev entries in the resource table are two variable
length arrays, the first one reference vring resources and the second
one is the virtio config space.  The virtio config space is used by
virtio to communicate status and configuration changes and must as such
be shared with the remote.

The reverted commit incorrectly made any changes to the virtio config
space only affect the local copy, in an attempt to allowing memory
protection of the shared resource table.

This reverts commit cda85293.
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>