[Encode] update mbpersec query 1 logic

If the field is supported, function sets non-zero value to this field.

_studio/mfx_lib/encode_hw/h264/src/mfx_h264_encode_hw.cpp

@@ -406,7 +406,7 @@ mfxStatus ImplementationAvc::Query(
         }
         if (mfxExtEncoderCapability * extCap = GetExtBuffer(*out))
         {
-            (void) extCap;
+            extCap->MBPerSec = 1;
             MFX_CHECK(MFX_HW_VAAPI != core->GetVAType(), MFX_ERR_UNSUPPORTED);
         }