fbdev: ssd1307fb: Use bool for ssd1307fb_deviceinfo flags

The .need_pwm and .need_chargepump fields in struct ssd1307fb_deviceinfo
are flags that can have only two possible values: 0 and 1.
Reduce kernel size by changing their types from int to bool.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Javier Martinez Canillas <javierm@redhat.com>
Signed-off-by: Helge Deller <deller@gmx.de>