MAINTAINERS: Use my kernel.org address for Intel PMIC work

Use my kernel.org address for Intel PMIC work. While here,
upgrade status to maintainer of PMIC MFD devices.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>