MAINTAINERS: Replace Siemens IPC related bouncing maintainers

Since complaints about bouncing maintainers raised [1] we have now a
replacement for maintainers that stepped away from their duties.

[1] https://www.spinics.net/lists/platform-driver-x86/msg47105.html

Signed-off-by: Benedikt Niedermayr <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Lee Jones <[e-mail]>

MAINTAINERS

···
 F:	drivers/media/usb/siano/
 
 SIEMENS IPC LED DRIVERS
-M:	Gerd Haeussler <[e-mail]>
-M:	Xing Tong Wu <[e-mail]>
+M:	Bao Cheng Su <[e-mail]>
+M:	Benedikt Niedermayr <[e-mail]>
 M:	Tobias Schaffner <[e-mail]>
 L:	[e-mail]
 S:	Maintained
 F:	drivers/leds/simple/
 
 SIEMENS IPC PLATFORM DRIVERS
-M:	Gerd Haeussler <[e-mail]>
-M:	Xing Tong Wu <[e-mail]>
+M:	Bao Cheng Su <[e-mail]>
+M:	Benedikt Niedermayr <[e-mail]>
 M:	Tobias Schaffner <[e-mail]>
 L:	[e-mail]
 S:	Maintained
···
 F:	include/linux/platform_data/x86/simatic-ipc.h
 
 SIEMENS IPC WATCHDOG DRIVERS
-M:	Gerd Haeussler <[e-mail]>
-M:	Xing Tong Wu <[e-mail]>
+M:	Bao Cheng Su <[e-mail]>
+M:	Benedikt Niedermayr <[e-mail]>
 M:	Tobias Schaffner <[e-mail]>
 L:	[e-mail]
 S:	Maintained