drm/msm/disp/dpu: fix two spelling mistakes

Trivial fix to spelling mistake in error messages
"diable" -> "disable"
"cliend" -> "client"

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>