openrisc: Switch to use export.h instead of module.h

Reduce dependencies on module.h since all we need here is export.h
for EXPORT_SYMBOL.

Fixes: f50169324d ("module.h: split out the EXPORT_SYMBOL into export.h")
Signed-off-by: Stafford Horne <shorne@gmail.com>

arch/openrisc/kernel/process.c

@@ -26,7 +26,7 @@
 #include <linux/sched/task.h>
 #include <linux/sched/task_stack.h>
 #include <linux/kernel.h>
-#include <linux/module.h>
+#include <linux/export.h>
 #include <linux/mm.h>
 #include <linux/stddef.h>
 #include <linux/unistd.h>