Enabled depthBiasClamp in SwiftShader's PhysicalDeviceFeatures, which
will also enable any dEQP tests that rely on it.

Bug: b/160463658
Tests: dEQP-VK.dynamic_state.rs_state.depth_bias_clamp
Change-Id: Ida3ae12d30fb70a3bd7e508e276fb9a1bfc96231
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/46848
Kokoro-Result: kokoro <noreply+kokoro@google.com>
Tested-by: Sean Risser <srisser@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>