MAINTAINERS: Add Aleksandar Rikalo as a reviewer for MIPS content

MAINTAINERS: Add Aleksandar Rikalo as a reviewer for MIPS content

Add Aleksandar Rikalo as a reviewer for MIPS content. Aleksandar
brings to us more than six years of experience in working on a variety
of development tools for MIPS architectures, and will greatly help
QEMU community understand and support intricacies of MIPS better.

Acked-by: Aleksandar Rikalo <arikalo@wavecomp.com>
Reviewed-by: Aleksandar Rikalo <arikalo@wavecomp.com>
Signed-off-by: Aleksandar Markovic <amarkovic@wavecomp.com>