net: wwan: iosm: fix memory leak in ipc_pcie_read_bios_cfg

ipc_pcie_read_bios_cfg() is using the acpi_evaluate_dsm() to
obtain the wwan power state configuration from BIOS but is
not freeing the acpi_object. The acpi_evaluate_dsm() returned
acpi_object to be freed.

Free the acpi_object after use.

Fixes: 7e98d785 ("net: iosm: entry point")
Signed-off-by: M Chetan Kumar <m.chetan.kumar@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>