x86/platform/intel-mid: Make intel_scu_device_register() static

There is no need anymore to have intel_scu_device_register() exported. Annotate
it with static keyword.

While here, rename to intel_scu_ipc_device_register() to use same pattern for
all SFI enumerated device register helpers.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: http://lkml.kernel.org/r/20170107123457.53033-1-andriy.shevchenko@linux.intel.com


Signed-off-by: Thomas Gleixner <tglx@linutronix.de>