Fix VK_KHR_shader_clock feature checks

Fix VK_KHR_shader_clock feature checks

The shader clock tests were not checking if the implementation supported
64-bit integers for tests that required the feature and they were
checking supported features at test instance creation time instead of
the specific checkSupport method for test cases.

Affected tests:
dEQP-VK.glsl.shader_clock.*

Components: Vulkan
VK-GL-CTS issue: 3187

Change-Id: I0dc86a4fae619c0d27628d97f0ac11c5def5ff4f