let LV_COLOR_FORMAT_RGB565_SWAPPED be a valid color format

[sandynomad]

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Change description

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In "esp_lvgl_port" the colorspace to be used is set in lvcl_port_display_cfg_t.

To change the endian of the color space with some ICs (ie: ST77916) it is necessary to enable swapping.

This patch permits LV_COLOR_FORMAT_RGB565_SWAPPED to be a valid color space (set in color_format).

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[espzav]

@sandynomad Thank you for this fix. Please solve pre-commit (https://docs.espressif.com/projects/esp-idf/en/latest/esp32/contribute/install-pre-commit-hook.html) and I will merge it.