MAINTAINERS: add myself to MIPS section

Signed-off-by: Shiyou Yin <yinshiyou-hf@loongson.cn>
Reviewed-by: Manojkumar Bhosale <Manojkumar.Bhosale@imgtec.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

MAINTAINERS

@@ -524,7 +524,7 @@ Operating systems / CPU architectures
 =====================================
 
 Alpha                                   Falk Hueffner
-MIPS                                    Manojkumar Bhosale
+MIPS                                    Manojkumar Bhosale, Shiyou Yin
 Mac OS X / PowerPC                      Romain Dolbeau, Guillaume Poirier
 Amiga / PowerPC                         Colin Ward
 Windows MinGW                           Alex Beregszaszi, Ramiro Polla