Introduced ilitek FBTFT support incl. touch ads7845 support

[pottendo]

Hi,
i've never done a pull request, so pls. be patient if I did something wrong.

This introduces support for another SPI based framebuffer device (Ilitek 9341) with touch screen (XPT2046/ads7845 compatible) support.
One shall use luckfox-config to select it.
Of course also the kernel driver and some user-space libraries need to be be built. I didn't know how to submit those changes in buildrootconfig (all around event processing, like the ts_* tools, etc.) and kernelconfig (the ads7845 driver in touchscreens and ili9341 driver in device drivers/staging/small tft).

Let me know, what you think,
pottendo

[luckfox-eng33]

Hi,
At the moment looking at this PR we probably won't accept it .
Because it's not generic enough and tends to confuse some users

[pottendo]

Hi,
if you let me know, what makes it 'generic' enough, I may add it.
I don't see too much difference to the other LCD driver (st7789), supported by the SDK, I've tried to keep my changes without effect on the this, so it's as specific as needed. Sure, the pinout with its connections need to be correct - but this applies to the st7789 as well - and this I've documented accordingly.
Anyway, for me it works - I'd be happy to support to bring this into the main SDK; if that's not in your interest, also fine for me.
bye, pottendo