backlight: tdo24m: Constify lcd_ops

'struct lcd_ops' is not modified by core backlight code, so it can be
made const for increased code safety.

Signed-off-by: Krzysztof Kozlowski <[e-mail]>
Reviewed-by: Daniel Thompson <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Lee Jones <[e-mail]>

drivers/video/backlight/tdo24m.c

···
 	return lcd->adj_mode(lcd, mode);
 }
 
-static struct lcd_ops tdo24m_ops = {
+static const struct lcd_ops tdo24m_ops = {
 	.get_power	= tdo24m_get_power,
 	.set_power	= tdo24m_set_power,
 	.set_mode	= tdo24m_set_mode,