Convert the module to be property provider agnostic and allow
it to be used on non-OF platforms.

Add mod_devicetable.h include.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>