MAINTAINERS: remove "PKUNITY SOC DRIVERS" entry

There no PkUnity drivers left, so remove the MAINTAINERS entry.
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Guenter Roeck <linux@roeck-us.net>

MAINTAINERS

@@ -13580,12 +13580,6 @@ F:	drivers/block/pktcdvd.c
 F:	include/linux/pktcdvd.h
 F:	include/uapi/linux/pktcdvd.h
 
-PKUNITY SOC DRIVERS
-M:	Guan Xuetao <gxt@pku.edu.cn>
-S:	Maintained
-W:	http://mprc.pku.edu.cn/~guanxuetao/linux
-T:	git git://github.com/gxt/linux.git
-
 PLANTOWER PMS7003 AIR POLLUTION SENSOR DRIVER
 M:	Tomasz Duszynski <tduszyns@gmail.com>
 S:	Maintained