sdl: Keep texture around, upload LCD-parts only
No need to create a new texture for every
rendered frame, unless the scaling method
has been adjusted.
We also don't need to upload the (unchanged)
player interface to GPU memory repeatedly.
+ Remove unused lcd_display_redraw &
having_new_lcd variables
Change-Id: I5bff6aa2d54347a3f2c3afba8d8d7eb9e39f77f7