Display color format / bits per pixel do not have public defines (BSP-283)

[TT-Qt]

Display color format / bits per pixel is not available from display.h or from esp-bsp.h ( via board specific header ).

In the BSP implementation these values are hardcoded.

Example from Korvo-2 BSP:

esp-bsp/esp32_s3_korvo_2/esp32_s3_korvo_2.c

Lines 235 to 236 in 160c0d6

	.color_space = ESP_LCD_COLOR_SPACE_BGR,
	.bits_per_pixel = 16,

[tore-espressif]

@TTauriainenQt yes, these values are constant and specific to the display that is shipped with korvo-2 board. Do you need to change these values?

[TT-Qt]

We need these values for the drawing engine as we have to know the framebuffer format in which we are drawing into. Now we have to use hardcoded values in our code and it would be nice to get them directly from the BSP header.

[TT-Qt]

Actually instead of ESP_LCD_COLOR_SPACE_BGR we would need to know the endianess. In case of Korvo-2 (and ESP-BOX) the framebuffer format needs to be big endian as the display interface uses such format.