regulator: core - Rework machine API to remove string based functions.

This improves the machine level API in order to configure
regulator constraints and consumers as platform data and removes the
old string based API that required several calls to set up each regulator.

The intention is to create a struct regulator_init_data, populate
it's fields with constraints, consumers devices, etc and then register
the regulator device from board.c in the standard Linux way.

e.g. regulator LDO2 (supplying codec and sim) platform data.

/* regulator LDO2 consumer devices */
static struct regulator_consumer_supply ldo2_consumers[] = {
{
	.dev	= &platform_audio_device.dev,
	.supply	= "codec_avdd",
},
{
	.dev	= &platform_sim_device.dev,
	.supply	= "sim_vcc",
}
};

/* regulator LDO2 constraints  */
static struct regulator_init_data ldo2_data = {
	.constraints = {
		.min_uV = 3300000,
		.max_uV = 3300000,
		.valid_modes_mask = REGULATOR_MODE_NORMAL,
		.apply_uV = 1,
	},
	.num_consumer_supplies = ARRAY_SIZE(ldo2_consumers),
	.consumer_supplies = ldo2_consumers,
};

/* machine regulator devices with thier consumers and constraints */
static struct platform_device wm8350_regulator_devices[] = {
{
	.name = "wm8350-regulator",
	.id = WM8350_LDO_2,
	.dev = {
		.platform_data = &ldo2_data,
	},
},
};

Changes in detail:-

  o Removed all const char* regulator config functions in machine API.
  o Created new struct regulator_init_data to contain regulator
    machine configuration constraints and consmuers.
  o Changed set_supply(), set_machine_constraints(),
    set_consumer_device_supply() to remove their string identifier
    parameters. Also made them static and moved functions nearer top of
    core.c.
  o Removed no longer used inline func to_rdev()
  o Added regulator_get_init_drvdata() to retrieve init data.
  o Added struct device* as parameter to regulator_register().
  o Changed my email address.

Signed-off-by: Eric Miao <eric.miao@marvell.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>