Fix feature requirements of sample mask tests

Fix feature requirements of sample mask tests

Some multisample sample mask tests required sampleRateShading feature
even though it is not actually needed.

This CL removes the feature requirement from those tests.

Following tests don't actually depend on the feature and no longer
require it:
dEQP-VK.pipeline.multisample_shader_builtin.sample_mask.pattern.*
dEQP-VK.pipeline.multisample_shader_builtin.sample_mask.write.*

Affects:
dEQP-VK.pipeline.multisample_shader_builtin.sample*

Components: Vulkan

VK-GL-CTS issue: 1745

Change-Id: Ib894149c9991edd10ae1961e7aaf6678eb0e6b5a