MAINTAINERS: Add entry for HI3660 SoC

Add MAINTAINERS entry for HI3660 SoC by adding the arch includes.
While doing so, adding myself as the co-maintainer for HISILICON
SoCs since I'm planning to maintain HI3660 SoC separately and considering
doing improvements to the existing HiSilicon SoC architecture.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
1 file changed