kernel: Map most files to use export.h instead of module.h

The changed files were only including linux/module.h for the
EXPORT_SYMBOL infrastructure, and nothing else.  Revector them
onto the isolated export header for faster compile times.

Nothing to see here but a whole lot of instances of:

  -#include <linux/module.h>
  +#include <linux/export.h>

This commit is only changing the kernel dir; next targets
will probably be mm, fs, the arch dirs, etc.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/kernel/irq_work.c b/kernel/irq_work.c
index 0e2cde4..3e460ea 100644
--- a/kernel/irq_work.c
+++ b/kernel/irq_work.c
@@ -6,7 +6,7 @@
  */
 
 #include <linux/kernel.h>
-#include <linux/module.h>
+#include <linux/export.h>
 #include <linux/irq_work.h>
 #include <linux/hardirq.h>