ili9341: add standard SPI driver

[sago35]

This PR adds a standard SPI driver for ili9341.
Unlike the approach in PR #242 , we tried to use the driver dedicated to each board if available.
For example, if there is no board-specific driver, such as the NRF52840, then the standard SPI driver is used.

The frame rate for examples/ili9341/pyportal_boaring is as follows

• specific driver
  • wioterminal (atsamd51)
    • 42 fps
• std-spi-driver
  • feather-nrf52840 (nrf52840)
    • 23 fps
  • feather-stm32f405 (stm32f405)
    • 30 fps

According to #196, the spi driver for stm32f405 seems to have a speed of 68 - 88 fps.
Once #196 is merged, the ili9341 on STM32F405 will run faster.
Until then, we can use the std-spi-driver.

• ILI9341: add SPI driver for STM32F4 #196 (comment)

[sago35]

Note that std-spi-driver does not differ in speed from specific-driver when used with atsamd51.

[sago35]

I have fixed the commit message and force-pushed it.

[sago35]

The following code, created by @ardnew , still works now.
With -opt=2, the fps is 68 fps.
After we merge this PR, it' s a good idea to use the SPI driver from #196 for the STM32F405.

#196

[deadprogram]

Thanks @sago35 worked correctly on my PyPortal. My frame rate was 37-38 fps:

tinygo flash -target pyportal ./examples/ili9341/pyportal_boing/

Then adding -opt=2 I got 47-48 fps

[deadprogram]

Now merging, thanks for working on this.