fbdev: ssd1307fb: Drop optional dependency

Only a single out of three devices need a PWM, so from driver it's
optional. Moreover it's a single driver in the entire kernel that
currently selects PWM. Unfortunately this selection is a root cause
of the circular dependencies when we want to enable optional PWM
for some other drivers that select GPIOLIB.

Fixes: a2ed00da5047 ("drivers/video: add support for the Solomon SSD1307 OLED Controller")
Signed-off-by: Andy Shevchenko <[e-mail]>
Signed-off-by: Helge Deller <[e-mail]>

drivers/video/fbdev/Kconfig

···
 	select FB_SYS_COPYAREA
 	select FB_SYS_IMAGEBLIT
 	select FB_DEFERRED_IO
-	select PWM
 	select FB_BACKLIGHT
 	help
 	  This driver implements support for the Solomon SSD1307