media: atomisp: restore missing 'return' statement

The input_system_configure_channel_sensor() function lost its final
return code in a previous patch:

drivers/staging/media/atomisp/pci/hive_isp_css_common/host/input_system.c: In function 'input_system_configure_channel_sensor':
drivers/staging/media/atomisp/pci/hive_isp_css_common/host/input_system.c:1649:1: error: control reaches end of non-void function [-Werror=return-type]

Restore what was there originally.

Link: https://lore.kernel.org/linux-media/20210802143820.1150099-1-arnd@kernel.org
Fixes: 728a5c64ae ("media: atomisp: remove dublicate code")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/staging/media/atomisp/pci/hive_isp_css_common/host/input_system.c

@@ -1646,6 +1646,8 @@ static input_system_err_t input_system_configure_channel_sensor(
 	default:
 		return INPUT_SYSTEM_ERR_PARAMETER_NOT_SUPPORTED;
 	}
+
+	return INPUT_SYSTEM_ERR_NO_ERROR;
 }
 
 // Test flags and set structure.