MAINTAINERS: add entry for Freescale SoC drivers

Add maintainer entry for Freescale SoC drivers including
the QE library and the GUTS driver now. Also add maintainer
for QE library.

Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
Acked-by: Scott Wood <oss@buserror.net>
Acked-by: Qiang Zhao <qiang.zhao@nxp.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>