Consolidate internal and external libmittos headers

src/libmittos/Makefile

@@ -31,7 +31,7 @@ $(OBJ): CPPFLAGS += $(DEPFLAGS)
 # Installation
 DESTDIR ?= $(BUILDROOT)/sysroot
 LIBDIR := $(DESTDIR)/usr/lib
-INCDIR := $(DESTDIR)/usr/include/mittos
+INCDIR := $(DESTDIR)/usr/include
 
 $(LIBDIR)/libmittos.a: libmittos.a
 	install -D $<  $@

src/libmittos/graphics/graphics.c

@@ -1,7 +1,7 @@
 #include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
-#include <graphics.h>
+#include <mittos/graphics.h>
 
 #define incptr(p, n) ((void *)(((uintptr_t)(p)) + (n)))
 

src/libmittos/include/mittos/graphics.h

@@ -1,5 +1,6 @@
 #pragma once
 #include <stdlib.h>
+#include <stdint.h>
 
 typedef struct {
   uint32_t width;