icd: stop generating icd-dispatch-entrypoints.c

Let ICDs define XGL entrypoints directly.  This requires the Intel ICD to
rename intelSomeEntryPoint() to xglSomeEntryPoint().  In addition, the ICD
needs to be linked with -Bsymbolic to make symbol resolving work for
xglGetProcAddr().

v2: use -Bsymbolic-functions
diff --git a/icd/intel/query.c b/icd/intel/query.c
index 1f00f98..46fbb2d 100644
--- a/icd/intel/query.c
+++ b/icd/intel/query.c
@@ -184,7 +184,7 @@
     return XGL_SUCCESS;
 }
 
-XGL_RESULT XGLAPI intelCreateQueryPool(
+ICD_EXPORT XGL_RESULT XGLAPI xglCreateQueryPool(
     XGL_DEVICE                                  device,
     const XGL_QUERY_POOL_CREATE_INFO*           pCreateInfo,
     XGL_QUERY_POOL*                             pQueryPool)
@@ -195,7 +195,7 @@
             (struct intel_query **) pQueryPool);
 }
 
-XGL_RESULT XGLAPI intelGetQueryPoolResults(
+ICD_EXPORT XGL_RESULT XGLAPI xglGetQueryPoolResults(
     XGL_QUERY_POOL                              queryPool,
     XGL_UINT                                    startQuery,
     XGL_UINT                                    queryCount,