regulator: axp20x: Add module alias

This allows the module to be autoloaded.

Together with 07949bf9 ("cpufreq: dt: allow driver to boot
automatically") this is sufficient to allow a modular kernel (such
as Debian's) to enable cpufreq on a Cubietruck.
Signed-off-by: NIan Campbell <ijc@hellion.org.uk>
Signed-off-by: NMark Brown <broonie@kernel.org>

drivers/regulator/axp20x-regulator.c

@@ -405,3 +405,4 @@ module_platform_driver(axp20x_regulator_driver);
 MODULE_LICENSE("GPL v2");
 MODULE_AUTHOR("Carlo Caione <carlo@caione.org>");
 MODULE_DESCRIPTION("Regulator Driver for AXP20X PMIC");
+MODULE_ALIAS("platform:axp20x-regulator");