ANDROID: sched: Export sched_domains_mutex for lockdep

If CONFIG_LOCKDEP is enabled, export `sched_domains_mutex` as it is
indirectly accessed by the macro `for_each_domain()`. This allows
vendors to call the `for_each_domain()` macro with CONFIG_LOCKDEP
enabled via the GKI_BUILD_CONFIG_FRAGMENT.

Bug: 176254015
Signed-off-by: Daniel Mentz <danielmentz@google.com>
Change-Id: Ia9f2989de41b2224c63855f2fd129cbeeac4f195
Signed-off-by: Will McVicker <willmcvicker@google.com>
(cherry picked from commit 7171a5de9832b53122a9787586e18e9523b5b47e)
(cherry picked from commit e2cdae06e22e6cfdbae696c5e40ad159a2cf9639)

kernel/sched/topology.c

diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index c480058..b60c3e1 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -6,6 +6,9 @@
 #include <trace/hooks/sched.h>
 
 DEFINE_MUTEX(sched_domains_mutex);
+#ifdef CONFIG_LOCKDEP
+EXPORT_SYMBOL_GPL(sched_domains_mutex);
+#endif
 
 /* Protected by sched_domains_mutex: */
 static cpumask_var_t sched_domains_tmpmask;