Add VK_EXT_device_drm_properties tests

Add VK_EXT_device_drm_properties tests

Verifies the basic API functionality works by
locating the device nodes associated with a Vulkan
device by matching them against the major and
minor device IDs reported by the extension.

Rather than assume the location of DRM device
nodes on the filesystem, these tests look them up
using libdrm's drmGetDevices[2]() function. This
requires some supporting code to properly load the
libraries, but should be more portable than simply
walking /dev/dri/*.

Components: Vulkan

New tests:

dEQP-VK.api.device_drm_properties.*

Change-Id: If9436e1595ad1132d5f542629c372a02fc3ed9e2