ST7789 fills the display with 0xffff color during its initialization.
This color may or may not be overwritten by a higher layer (framebuffer
or lcd driver for example). The color remains on the display until
application UI is started if not overwritten by the higher layer before.
This commit adds configuration option LCD_ST7789_DEFAULT_COLOR that
allows to set the default background color. This may avoid shining
display with, for example, white color for an extensive amount of time.
The default value is set to 0xffff previously hard-coded in the driver,
therefore current implementations will not notice the change.
Signed-off-by: Michal Lenc <michallenc@seznam.cz>
Michal Lenc
a8d4ed910d