vulkan: Update templates for generated extensions

When the swapchain extensions were added to the API file, only
the libvulkan/get_proc_addr.cpp template was updated. This change
updates the remaining templates, so that when used they generate the
appropriate output with the new API file:

- libvulkan/entry.cpp: Remove hardcoded extension entry points, now
  that they're autogenerated.
- nulldrv/null_driver_gen.cpp: Exclude all extension entry points;
  this only works because the API currently only includes entry points
  implemented by the loader. Eventually we'll want to replace this
  with an extension blacklist.

Change-Id: Id6ea11fb739390d8262fa5ce77c213fbbdeb0148
(cherry picked from commit 1d40de6ecdd74c47ebd40fadd5926cc2984cc91c)
diff --git a/vulkan/api/vulkan.api b/vulkan/api/vulkan.api
index 23d9951..7616740 100644
--- a/vulkan/api/vulkan.api
+++ b/vulkan/api/vulkan.api
@@ -4335,6 +4335,20 @@
 // Extensions //
 ////////////////
 
+@extension("VK_EXT_KHR_swapchain")
+cmd VkResult vkGetPhysicalDeviceSurfaceSupportKHR(
+        VkPhysicalDevice                        physicalDevice,
+        u32                                     queueFamilyIndex,
+        const VkSurfaceDescriptionKHR*          pSurfaceDescription,
+        VkBool32*                               pSupported) {
+    physicalDeviceObject := GetPhysicalDevice(physicalDevice)
+
+    supported := ?
+    pSupported[0] = supported
+
+    return ?
+}
+
 @extension("VK_EXT_KHR_device_swapchain")
 cmd VkResult vkGetSurfacePropertiesKHR(
         VkDevice                                 device,
@@ -4467,19 +4481,6 @@
     return ?
 }
 
-@extension("VK_EXT_KHR_swapchain")
-cmd VkResult vkGetPhysicalDeviceSurfaceSupportKHR(
-        VkPhysicalDevice                        physicalDevice,
-        u32                                     queueFamilyIndex,
-        const VkSurfaceDescriptionKHR*          pSurfaceDescription,
-        VkBool32*                               pSupported) {
-    physicalDeviceObject := GetPhysicalDevice(physicalDevice)
-
-    supported := ?
-    pSupported[0] = supported
-
-    return ?
-}
 
 ////////////////
 // Validation //