Remove uses of GrPixelConfig in GrVkCaps and other vk files.

Bug: skia:6718
Change-Id: I2f0d38b2b7a68a424732ced56e8b6c7e5965a722
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/235023
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Greg Daniel <egdaniel@google.com>
diff --git a/src/gpu/vk/GrVkRenderTarget.cpp b/src/gpu/vk/GrVkRenderTarget.cpp
index 819eb0e..d7d53fb 100644
--- a/src/gpu/vk/GrVkRenderTarget.cpp
+++ b/src/gpu/vk/GrVkRenderTarget.cpp
@@ -139,8 +139,7 @@
     SkASSERT(VK_NULL_HANDLE != info.fImage);
 
     SkASSERT(1 == info.fLevelCount);
-    VkFormat pixelFormat;
-    GrPixelConfigToVkFormat(desc.fConfig, &pixelFormat);
+    VkFormat pixelFormat = info.fFormat;
 
     VkImage colorImage;