Remove more stale renderer plumbing

alphaReference is not used. It previously provided a configurable
threshold for alphaToCoverage, before that was explicitly managed by
pipeline state.

The sample mask is not dynamic state, so it can never change between
draws without a complete context change.

sRGB write control is not context state, it is determined by the image
view format.

Bug: b/118386749
Change-Id: Id631732fad52cf6b75c1635bcd7ef464dda10e54
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/29649
Tested-by: Chris Forbes <chrisforbes@google.com>
Presubmit-Ready: Chris Forbes <chrisforbes@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>
diff --git a/src/Vulkan/VkCommandBuffer.cpp b/src/Vulkan/VkCommandBuffer.cpp
index b713275..f347421 100644
--- a/src/Vulkan/VkCommandBuffer.cpp
+++ b/src/Vulkan/VkCommandBuffer.cpp
@@ -429,7 +429,7 @@
 		if (attachmentReference.attachment != VK_ATTACHMENT_UNUSED)
 		{
 			auto attachment = renderPassFramebuffer->getAttachment(attachmentReference.attachment);
-			renderer->setRenderTarget(i, attachment, 0);
+			renderer->setRenderTarget(i, attachment);
 		}
 	}
 
@@ -439,11 +439,11 @@
 		auto attachment = renderPassFramebuffer->getAttachment(attachmentReference->attachment);
 		if (attachment->hasDepthAspect())
 		{
-			renderer->setDepthBuffer(attachment, 0);
+			renderer->setDepthBuffer(attachment);
 		}
 		if (attachment->hasStencilAspect())
 		{
-			renderer->setStencilBuffer(attachment, 0);
+			renderer->setStencilBuffer(attachment);
 		}
 	}
 }