The Vulkan min/maxTexelGatherOffset VkPhysicalDeviceLimits correspond to
OpenGL's GL_MIN/MAX_PROGRAM_TEXTURE_GATHER_OFFSET params. Pass them
directly through.

Bug: angleproject:3605
Change-Id: Ic6a22bbe30ee2b0baaeaa62b6e26dc844c2ad82d
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1793357Reviewed-by: Courtney Goeltzenleuchter <courtneygo@google.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Tobin Ehlis <tobine@google.com>