[PATCH V2 3/3] staging: vchiq_arm: move state dump to debugfs

[Ricardo B. Marliere]

Tested on both aarch64 and armv7l on a RPi 3B using the vchiq_test tool.

/sys/kernel/debug/vchiq/state
/sys/kernel/debug/vchiq/clients/**/trace
/sys/kernel/debug/vchiq/clients/**/use_count
contents are fine.

Tested-by: Ricardo B. Marliere <ricardo at marliere.net>