ath10k: fix some spelling mistakes

Trivial fix to some spelling mistakes in ath10k_err and ath10k_dbg
messages:
"capablity" -> "capability"
"registed" -> "registered"

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>