esp_lcd set contrast function (IDFGH-14218)

[mutatrum]

Is your feature request related to a problem?

The SSD1306 and SH1106 displays have a contrast command (0x81), which is currently not exposed through esp_lcd_panel_ops. Other panels probably have similar contrast settings.

Describe the solution you'd like.

Addition of a esp_lcd_panel_contrast function to set the contrast.

Describe alternatives you've considered.

Directly executing the command:

#define SSD1306_CMD_CONTRAST 0x81
ESP_ERROR_CHECK_WITHOUT_ABORT(esp_lcd_panel_io_tx_param(io_handle, SSD1306_CMD_CONTRAST, (uint8_t[]) { 0x80 }, 1));

which is not very nice.

Additional context.

No response

[suda-morris]

Thanks @mutatrum for the suggestion, we may consider this feature.