remoteproc: imx_rproc: fix a couple off by one bugs

The priv->mem[] array has IMX7D_RPROC_MEM_MAX elements so the > should
be >= to avoid writing one element beyond the end of the array.

Fixes: a0ff4aa6 ("remoteproc: imx_rproc: add a NXP/Freescale imx_rproc driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>