Include in next: Switch SpacemiT SoC tree's repo

Hi Linux-Next Maintainer,

Previously, the SpacemiT SoC tree was hosted in github.com[1],
while now we've created a new kernel tree at kernel.org[2], so please help to update the repo url for linux-next tree to the new one, and the other info should being unchanged, that's:
branch for master: for-next
branch for pending-fixes: fixes

I will also switch to new repo for sending next Pull-Request to
SoC tree maintainer.

Thank you

[1] https://github.com/spacemit-com/linux
[2] https://git.kernel.org/pub/scm/linux/kernel/git/spacemit/linux.git/

Yixun Lan (dlan)

I've updated the -next configuration, the new locations will be used from tomorrow.