Merge pull request #21883 from SergeyIvanov87:gapi_vpl_linux

G-API: VPL Source turn on Linux CPU version

* Turn on linux compilation

* Apply comments

* Change new files headline

* Add license header

modules/gapi/include/opencv2/gapi/streaming/onevpl/accel_types.hpp

@@ -20,6 +20,7 @@ namespace onevpl {
 enum class AccelType: uint8_t {
     HOST,
     DX11,
+    VAAPI,
 
     LAST_VALUE = std::numeric_limits<uint8_t>::max()
 };