drm/panel: novatek,nt39016: Add missing CR to error messages

If you pass a string that is not terminated with a carriage return to
dev_err(), it will eventually be printed with a carriage return, but
not right away, since the kernel will wait for a pr_cont().

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200811002240.55194-3-paul@crapouillou.net