main/directfb: Add patch to automatically detect touchscreens using tslib

At the moment, directfb requires explicitly setting a TSLIB_TSDEVICE environment variable with the path to the touchscreen input event device (i.e. /dev/input/eventX). These paths are not stable, the numbering is different on each device and can change with kernel updates.

At some point, tslib was updated with a ts_setup() function that automatically detects the touchscreen based on the available input devices, without having to set the environment variable. Unfortunately, directfb was never updated to use it. directfb has been dead upstream for years, but it is still used in postmarketOS because it is the only SDL backend that can write to a fbdev. The patch is quite simple and straightforward, so maybe we can add it here?

Added an extra commit that fixes some linter/abuild warnings of the package.

Cc: @craftyguy