Remove is_arvr_mode() from xplat/executorch/runtime/core/portable_type/c10/c10/targets.bzl (#11830)

Summary:

Remove is_arvr_mode() from fbcode/executorch/runtime/core/portable_type/c10/c10/targets.bzl.

This is an effort to unify the xplat and rl target graphs in the citadel orchestrator
See post for context https://fb.workplace.com/groups/3454295018049629/permalink/3734068433405618/

Reviewed By: autozimu, swolchok

Differential Revision: D76755925

Author: Michael Chien

runtime/core/portable_type/c10/c10/targets.bzl

@@ -68,9 +68,10 @@ def define_common_targets():
         xplat_exported_deps = [
             "//xplat/caffe2:aten_header",
             "//xplat/caffe2/c10:c10_headers",
-            ("//xplat/caffe2:ovrsource_aten_Config.h"
-            if is_arvr_mode() else "//xplat/caffe2:generated_aten_config_header"),
-        ], # + get_sleef_deps(), # TODO: enable Sleef in xplat?
+        ] + select({
+            "DEFAULT": ["//xplat/caffe2:generated_aten_config_header"],
+            "ovr_config//build_mode:arvr_mode": ["//xplat/caffe2:ovrsource_aten_Config.h"],
+        }), # + get_sleef_deps(), # TODO: enable Sleef in xplat?
         fbcode_exported_deps = ([
             "//caffe2:aten-headers-cpu",
             "//caffe2:generated-config-header",