hwmon: (mcp3021) Remove use of i2c_match_id()

The function i2c_match_id() is used to fetch the matching ID from
the i2c_device_id table. This is often used to then retrieve the
matching driver_data. This can be done in one step with the helper
i2c_get_match_data().

This helper has a couple other benefits:
* It doesn't need the i2c_device_id passed in so we do not need
to have that forward declared, allowing us to remove those or
move the i2c_device_id table down to its more natural spot
with the other module info.
* It also checks for device match data, which allows for OF and
ACPI based probing. That means we do not have to manually check
those first and can remove those checks.

Signed-off-by: Andrew Davis <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Guenter Roeck <[e-mail]>

drivers/hwmon/mcp3021.c

···
 	.info = mcp3021_info,
 };
 
-static const struct i2c_device_id mcp3021_id[];
-
 static int mcp3021_probe(struct i2c_client *client)
 {
 	struct mcp3021_data *data = NULL;
 	struct device_node *np = client->dev.of_node;
 	struct device *hwmon_dev;
+	enum chips type;
 
 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
 		return -ENODEV;
···
 			data->vdd = MCP3021_VDD_REF_DEFAULT;
 	}
 
-	switch (i2c_match_id(mcp3021_id, client)->driver_data) {
+	type = (uintptr_t)i2c_get_match_data(client);
+	switch (type) {
 	case mcp3021:
 		data->sar_shift = MCP3021_SAR_SHIFT;
 		data->sar_mask = MCP3021_SAR_MASK;