st7789 display driver

[gemu2015]

Description:

add driver for st7789 (240x240) TFT LCD

works and tested with both devices

https://www.banggood.com/de/1_3-Inch-IPS-TFT-LCD-Display-240240-Color-HD-LCD-Screen-3_3V-ST7789-Driver-Module-p-1383404.html?gmcCountry=DE&currency=EUR&createTmp=1&utm_source=googleshopping&utm_medium=cpc_bgs&utm_content=frank&utm_campaign=frank-ssc-de-all-css-0623&ad_id=443951763558&gclid=EAIaIQobChMIoO25rdeE6wIVheF3Ch3zMw6vEAQYAiABEgJMZPD_BwE&cur_warehouse=CN

https://www.banggood.com/de/LILYGO-TTGO-T-Watch-2020-ESP32-Main-Chip-1_54-Inch-Touch-Display-Programmable-Wearable-Environmental-Interaction-Watch-p-1671427.html?gmcCountry=DE&currency=EUR&createTmp=1&utm_source=googleshopping&utm_medium=cpc_bgs&utm_content=frank&utm_campaign=frank-ssc-de-all-css-0623&ad_id=443951763558&gclid=EAIaIQobChMIttKju9eE6wIVcSB7Ch2k8w9WEAQYASABEgLtv_D_BwE&cur_warehouse=CN

Checklist:

• The pull request is done against the latest dev branch
• Only relevant files were touched
• Only one feature/fix was added per PR.
• The code change is tested and works on Tasmota core ESP8266 V.2.7.3.2
• The code change is tested and works on core ESP32 V.1.12.2
• I accept the CLA.

NOTE: The code change must pass CI tests. Your PR cannot be merged unless tests pass