add H.265 stream type

Change-Id: Ic8e17f949f245ad6fe26fb8078e0545fe5b35daa
Reviewed-on: https://code.wireshark.org/review/3116
Reviewed-by: Martin Kaiser <wireshark@kaiser.cx>
(cherry picked from commit 831c1f2fe1586c7d8d5aa9767033ccba8b64da91)
Reviewed-on: https://code.wireshark.org/review/3120