When mcusys is off, rdist_ctx will save the rdist data of the last core.
In the case of the last core plug off, the data of other cores will be
inconsistent with the data in rdist_ctx.
Therefore, each core needs to use a dedicated context.
Signed-off-by: Runyang Chen <runyang.chen@mediatek.com>
Change-Id: Ic9501f4da219cf906c0e348982be3f550c3ba30b