of/unittest: Remove unnecessary module.h header inclusion

The OF_UNITTEST Kconfig symbol is bool so this unittest can only be
built-in and not build as a module. Also, nothing defined in this
header file used so is not necessary to include it.
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Rob Herring <robh@kernel.org>

drivers/of/unittest.c

@@ -8,7 +8,6 @@
 #include <linux/err.h>
 #include <linux/errno.h>
 #include <linux/hashtable.h>
-#include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_fdt.h>
 #include <linux/of_irq.h>