Revert "Bump maxUniformBindingSize to 2^16 from 2^14"

This reverts commit 1a57ee9d4e.

Reason for revert: Swiftshader does not support 2^16 at the moment, and this is causing all Swiftshader tests to be skipped silently.

Original change's description:
> Bump maxUniformBindingSize to 2^16 from 2^14
>
> This was upped in https://github.com/gpuweb/gpuweb/pull/2159
>
> Bug: dawn:1173
> Change-Id: I98d46b9b5a339280d21ddcb2ab039ce7ebce4ec3
> Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/71608
> Commit-Queue: Brandon Jones <bajones@chromium.org>
> Auto-Submit: Corentin Wallez <cwallez@chromium.org>
> Reviewed-by: Brandon Jones <bajones@chromium.org>

TBR=cwallez@chromium.org,enga@chromium.org,bajones@chromium.org,bajones@google.com,dawn-scoped@luci-project-accounts.iam.gserviceaccount.com

Change-Id: Ib7d6023adac3f99b8e7238035eed2a16f2ced6d0
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: dawn:1173
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/71840
Reviewed-by: Austin Eng <enga@chromium.org>
Commit-Queue: Loko Kung <lokokung@google.com>

src/dawn_native/Limits.cpp

@@ -43,7 +43,7 @@
     X(Higher,           maxStorageBuffersPerShaderStage,     8,     8) \
     X(Higher,          maxStorageTexturesPerShaderStage,     4,     4) \
     X(Higher,           maxUniformBuffersPerShaderStage,    12,    12) \
-    X(Higher,               maxUniformBufferBindingSize, 65536, 65536) \
+    X(Higher,               maxUniformBufferBindingSize, 16384, 16384) \
     X( Lower,           minUniformBufferOffsetAlignment,   256,   256) \
     X( Lower,           minStorageBufferOffsetAlignment,   256,   256) \
     X(Higher,                          maxVertexBuffers,     8,     8) \