imx8m-blk-ctrl: set ISI panic write hurry level

Apparently, ISI needs cache settings similar to LCDIF.
Otherwise we get artefacts in the image.
Tested on i.MX8MP.

Signed-off-by: Krzysztof Hałasa <khalasa@piap.pl>
Link: https://lore.kernel.org/r/m3ldr69lsw.fsf@t19.piap.pl


Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>