linux-postmarketos-omap: Update to 6.9.3

Enabled CONFIG_NLS_ASCII - #2874 (closed)

Revert logic for iio-rescale.c - https://lore.kernel.org/all/20220524075448.140238-1-linus.walleij@linaro.org/ Enables light and proximity sensor!

Fix whiteline issues

Remove patch for power controller as it is mainlined - #2825 (closed)

Update to 6.9.3

TODO:

• Check clk32kg - https://lore.kernel.org/lkml/20230916100515.1650336-6-andreas@kemnade.info/ (Fixes #2672 (closed))
• Check it works fine on other omap devices @akemnade @sicelo @antoni.aloytorrens

It would be great if we get this merged into v24.06