scripts: Fixup vulkan.py for trunkmerges in VT
scripts: Fixup vulkan.py for trunkmerges in VT

VulkanTools still uses some of the removed vulkan.py functionality.
Adding back in to facilitate trunk merges.

Change-Id: I92b4793f551e5d2afa46f353984a97ee87d831f4

KhronosGroup/Vulkan-Tools,KhronosGroup/Vulkan-Tools,KhronosGroup/Vulkan-Tools,KhronosGroup/Vulkan-Tools