device-odroid-hc2: disable big.LITTLE switcher by default (+ take over maintainership)

The linux-edge kernel enables the BL_SWITCHER kernel option, which enables an in-kernel big.LITTLE switcher - with it enabled, only 4 cores are enabled at a time, and the kernel switches between the big and little cores. However, in a server workload, it's more likely that a user wants all 8 cores to work simultaneously.

Disable the switcher by default by providing the no_bL_switcher cmdline option. It can still be re-enabled by writing 1 to /sys/kernel/bL_switcher/active.