x86/platform/intel-mid: Mark regulators explicitly defined

x86/platform/intel-mid: Mark regulators explicitly defined

Intel MID platforms are using explicitly defined regulators.

Let the regulator core know that we do not have any additional
regulators left. This lets it substitute unprovided regulators with
dummy ones.

Without this change when CONFIG_REGULATOR=y the USB driver fails on getting
"vbus" regulator and SDHCI can't get "vmmc" and "vqmmc" regulators either.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1468071929-77383-1-git-send-email-andriy.shevchenko@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>