remoteproc: imx_rproc: Fix invalid loaded resource table detection

remoteproc: imx_rproc: Fix invalid loaded resource table detection

imx_rproc_elf_find_loaded_rsc_table() may incorrectly report a loaded
resource table even when the current firmware does not provide one.

When the device tree contains a "rsc-table" entry, priv->rsc_table is
non-NULL and denotes where a resource table would be located if one is
present in memory. However, when the current firmware has no resource
table, rproc->table_ptr is NULL. The function still returns
priv->rsc_table, and the remoteproc core interprets this as a valid loaded
resource table.

Fix this by returning NULL from imx_rproc_elf_find_loaded_rsc_table() when
there is no resource table for the current firmware (i.e. when
rproc->table_ptr is NULL). This aligns the function's semantics with the
remoteproc core: a loaded resource table is only reported when a valid
table_ptr exists.

With this change, starting firmware without a resource table no longer
triggers a crash.

Fixes: e954a1bd1610 ("remoteproc: imx_rproc: Use imx specific hook for find_loaded_rsc_table")
Cc: stable@vger.kernel.org
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Acked-by: Daniel Baluta <daniel.baluta@nxp.com>
Link: https://lore.kernel.org/r/20260129-imx-rproc-fix-v3-1-fc4e41e6e750@nxp.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>