Declare context for emmc for other targets

    Declare context for emmc and give permission for RIDL/LogKit. RIDL needs to
    be able to write to sysfs dload to enable emmc crashdumps. It also needs to
    be able to read/write to the rawdump device block to copy the crashdump for
    post processing and mark it as read.

    Initial support was for 8937. This adds support for 8996, 8953, 8976, and
    msmcobalt. It also uses symbolic link add for both LogKit II and LogKit III.

CRs-Fixed: 1002379
Change-Id: Ic7df28c392fbc918654da871dfbeef50b72765db