mfd: bcm590xx: Fix modalias prefix

This is a i2c driver, so uses i2c prefix in modalias.
Signed-off-by: NAxel Lin <axel.lin@ingics.com>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

drivers/mfd/bcm590xx.c

@@ -97,4 +97,4 @@ module_i2c_driver(bcm590xx_i2c_driver);
 MODULE_AUTHOR("Matt Porter <mporter@linaro.org>");
 MODULE_DESCRIPTION("BCM590xx multi-function driver");
 MODULE_LICENSE("GPL v2");
-MODULE_ALIAS("platform:bcm590xx");
+MODULE_ALIAS("i2c:bcm590xx");