UPSTREAM: ath10k: detach coredump.c from debug.c

Now coredump is totally separate from debug.c and doesn't depend on
CONFIG_ATH10K_DEBUGFS anymore, only on CONFIG_DEV_COREDUMP. Also remove
leftovers from the removed debugfs file support.

Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
Git-commit: e2fcf60c6fe84f9540b7420a790cdc3eb3ae47d5
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/kvalo/ath.git


Change-Id: I9f244937bae84a6e13640e28df444fd252585aa6
Signed-off-by: Dundi Raviteja <dundi@codeaurora.org>