nulldrv: Implement GetPhysicalDeviceSurfaceCapabilitiesKHR better
nulldrv: Implement GetPhysicalDeviceSurfaceCapabilitiesKHR better

Fill out the struct with plausible values.

Signed-off-by: Chris Forbes <c3279c50043e18e9442c1ae071cafa0e7a4ca967@google.com>

sashinde/VulkanTools,sashinde/VulkanTools,sashinde/VulkanTools,sashinde/VulkanTools