Currently the driver hardcodes the default values to 96x16 pixels but this
default resolution depends on the controller. The datasheets for the chips
describes the following display controller resolutions:

 - SH1106:  132 x 64 Dot Matrix OLED/PLED
 - SSD1305: 132 x 64 Dot Matrix OLED/PLED
 - SSD1306: 128 x 64 Dot Matrix OLED/PLED
 - SSD1307: 128 x 39 Dot Matrix OLED/PLED
 - SSD1309: 128 x 64 Dot Matrix OLED/PLED

Add this information to the devices' info structures, and use it set as a
default if not defined in DT rather than hardcoding to an arbitrary value.

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20230609170941.1150941-2-javierm@redhat.com