Added support for Pimoroni Display Hat Mini

[makerph]

Description

Added support for Pimoroni Display Hat Mini

• 2.0” 320x240 pixel IPS LCD screen, connected via SPI (~220 PPI, 65K colours)

Motivation and Context

I wanted to have a large display with larger resolution in phat format. There are existing LCD Hat support but text is too small for my old eyes.

• [ ] I have raised an issue to propose this change (required)

How Has This Been Tested?

Tested this on Raspberry Pi Zero W with fresh 1.5.5 Image

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [x] My code follows the code style of this project.
• [ ] My change requires a change to the documentation.
• [ ] I have updated the documentation accordingly.
• [x] I've read the CONTRIBUTION guide
• [ ] I have signed-off my commits with git commit -s

[DizHell]

Merci @do-ki Testé ce jour et c'est fonctionnel.

Thanks @do-ki Tested today and it's functional.