drivers/clk: don't use module_init in clk-nomadik.c which is non-modular

The clk-nomadik.o is built for ARCH_NOMADIK -- which is bool, and
hence this code is either present or absent. It will never be
modular, so using module_init as an alias for __initcall can be
somewhat misleading.

Fix this up now, so that we can relocate module_init from
init.h into module.h in the future. If we don't do this, we'd
have to add module.h to obviously non-modular code, and that
would be a worse thing.

Note that direct use of __initcall is discouraged, vs. one
of the priority categorized subgroups. As __initcall gets
mapped onto device_initcall, our use of device_initcall
directly in this change means that the runtime impact is
zero -- it will remain at level 6 in initcall ordering.

Cc: Mike Turquette <[e-mail]>
Cc: [e-mail]
Signed-off-by: Paul Gortmaker <[e-mail]>

drivers/clk/clk-nomadik.c

···
 			    NULL, NULL, &nomadik_src_clk_debugfs_ops);
 	return 0;
 }
-
-module_init(nomadik_src_clk_init_debugfs);
+device_initcall(nomadik_src_clk_init_debugfs);
 
 #endif