Multiple places in the codebase use SPV_VERSION_1_1, which makes
updating the SPIR-V version a nuissance. Now only VkConfig.hpp
tracks that information.

Bug: b/172837769
Change-Id: I9ba09b431e48e2205cf0d8b428417b72a3f514cb
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/50128Reviewed-by: Alexis Hétu <sugoi@google.com>
Kokoro-Result: kokoro <noreply+kokoro@google.com>
Tested-by: Sean Risser <srisser@google.com>