add set_brightness in framebuffer.h (#1659)

old-commit-hash: 8ad1135e80f93b19bb2f0a6b4c7531a9b5eb7d8a

selfdrive/common/framebuffer.h

@@ -1,5 +1,4 @@
-#ifndef FRAMEBUFFER_H
-#define FRAMEBUFFER_H
+#pragma once
 
 #ifdef __cplusplus
 extern "C" {
@@ -13,6 +12,7 @@ FramebufferState* framebuffer_init(
 
 void framebuffer_set_power(FramebufferState *s, int mode);
 void framebuffer_swap(FramebufferState *s);
+bool set_brightness(int brightness);
 
 /* Display power modes */
 enum {
@@ -40,9 +40,6 @@ enum {
     HWC_POWER_MODE_DOZE_SUSPEND  = 3,
 };
 
-
 #ifdef __cplusplus
 }
 #endif
-
-#endif