drm/dbi: Print errors for mipi_dbi_command()

drm/dbi: Print errors for mipi_dbi_command()

The macro mipi_dbi_command() does not report errors unless you wrap it
in another macro to do the error reporting.

Report a rate-limited error so we know what is going on.

After this any code wishing to send command arrays can rely on
mipi_dbi_command() providing an appropriate error message if something
goes wrong.

Suggested-by: Noralf Trønnes <noralf@tronnes.org>
Suggested-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Noralf Trønnes <noralf@tronnes.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210702135601.3952726-1-linus.walleij@linaro.org