[SYCL][Doc] Fix link in sycl_ext_oneapi_root_group (#8715)

Signed-off-by: John Pennycook <[email protected]>

Author: Pennycook

sycl/doc/extensions/proposed/sycl_ext_oneapi_root_group.asciidoc

@@ -44,7 +44,7 @@ This extension also depends on the following other SYCL extensions:
 
 * link:../experimental/sycl_ext_oneapi_properties.asciidoc[
   sycl_ext_oneapi_properties]
-* link:../proposed/sycl_ext_oneapi_kernel_properties.asciidoc[
+* link:../experimental/sycl_ext_oneapi_kernel_properties.asciidoc[
   sycl_ext_oneapi_kernel_properties]