drm_hwcomposer: libdrmgetter: fix RGB565 format translation
FOSS graphic components (gbm_gralloc, mesa3d) are translating HAL_PIXEL_FORMAT_RGB_565 to DRM_FORMAT_RGB565 without swapping the R and B components. Same must be done here.
Fixes wrong colors in some games (i.e. Pixel Wheels).
Edited by Roman Stratiienko