x86: don't use module_init in non-modular intel_mid_vrtc.c

The X86_INTEL_MID option 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 is rather 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: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

arch/x86/platform/intel-mid/intel_mid_vrtc.c

@@ -173,5 +173,4 @@ static int __init intel_mid_device_create(void)
 
 	return platform_device_register(&vrtc_device);
 }
-
-module_init(intel_mid_device_create);
+device_initcall(intel_mid_device_create);