[HW] Waveshare Raspberry Pi Pico LCD Modules as Shields

[rexut]

Is this request related to a missing driver support for a particular hardware platform, SoC or board? Please describe.
I need support for Waveshare Pico LCD Modules as shields. The following shield should be supported:

• Waveshare Pico LCD 0.96, 65K colors, 80 × 160 pixels, driver: ST7735S
• Waveshare Pico LCD 1.3, 65K colors, 240 × 240 pixels, driver: ST7789VW
• Waveshare Pico LCD 1.44, 65K colors, 128 × 128 pixels, driver: ST7735S
• Waveshare Pico LCD 1.8, 65K colors, 128 × 160 pixels, driver: ST7735S
• Waveshare Pico-ResTouch-LCD-2.8, 262K colors, 240 × 320 pixels, driver: ST7789 / XPT2046

In this early first stage the Zephyr upstream samples "Shell on USB console", "LCD Orientation and Bit Order Test" and "LVGL Basic Sample" should be usable.

Describe why you are asking for this support?
With this support the board+shield variation for display based systems will scaling up.

I'm preparing a changeset for PR. I'll maintain the new board for Bridle and later contribute and maintain to/in Zephyr upstream.

Additional context
The new shields support will coming together with RPi Pico R3 connector support as currently provided by Bridle only.