lib/xe: set hwconfig NULL for unsupported platforms

There are hardware platforms which are not supporting
hwconfig table, for example ADLS. Querying hwconfig
on unsupported platforms leads to assert and failure
for some of tests like,
./build/tests/xe_module_load --r load

drm/xe/kernel#3683



Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Jan Maslak <jan.maslak@intel.com>
Fixes: 37a230e5 ("lib/xe_query: add hwconfig to xe_device")
Signed-off-by: Tejas Upadhyay <tejas.upadhyay@intel.com>
Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>

lib/xe/xe_query.c

@@ -51,7 +51,8 @@ static uint32_t *xe_query_hwconfig_new(int fd, uint32_t *hwconfig_size)
 
 	/* Perform the initial query to get the size */
 	igt_assert_eq(igt_ioctl(fd, DRM_IOCTL_XE_DEVICE_QUERY, &query), 0);
-	igt_assert_neq(query.size, 0);
+	if (!query.size)
+		return NULL;
 
 	hwconfig = malloc(query.size);
 	igt_assert(hwconfig);
@@ -858,7 +859,8 @@ uint32_t *xe_hwconfig_lookup_value(int fd, enum intel_hwconfig attribute, uint32
 	igt_assert(xe_dev);
 
 	hwconfig = xe_dev->hwconfig;
-	igt_assert(hwconfig);
+	if (!hwconfig)
+		return NULL;
 
 	/* Extract the value from the hwconfig */
 	pos = 0;