video: fbdev: ssd1307fb: Cache address ranges

Cache the column and page ranges, to avoid doing unneeded I2C transfers
when the values haven't changed.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210727134730.3765898-6-geert@linux-m68k.org