Cleanup includes

Improved manually with the help of neovim LSP warnings and iwyu:

    iwyu -Ibuilddir/app/ -Iapp/src/ app/src/XXX.c

app/src/hid/hid_event.h

@@ -3,6 +3,7 @@
 
 #include "common.h"
 
+#include <stddef.h>
 #include <stdint.h>
 
 #define SC_HID_MAX_SIZE 15

app/src/hid/hid_gamepad.c

@@ -2,6 +2,8 @@
 
 #include <assert.h>
 #include <inttypes.h>
+#include <stddef.h>
+#include <sys/types.h>
 
 #include "util/binary.h"
 #include "util/log.h"

app/src/hid/hid_gamepad.h

@@ -4,6 +4,7 @@
 #include "common.h"
 
 #include <stdbool.h>
+#include <stdint.h>
 
 #include "hid/hid_event.h"
 #include "input_events.h"

app/src/hid/hid_keyboard.c

@@ -1,5 +1,6 @@
 #include "hid_keyboard.h"
 
+#include <assert.h>
 #include <string.h>
 
 #include "util/log.h"

app/src/hid/hid_keyboard.h

@@ -4,6 +4,7 @@
 #include "common.h"
 
 #include <stdbool.h>
+#include <stdint.h>
 
 #include "hid/hid_event.h"
 #include "input_events.h"

app/src/hid/hid_mouse.c

@@ -1,5 +1,7 @@
 #include "hid_mouse.h"
 
+#include <stdint.h>
+
 // 1 byte for buttons + padding, 1 byte for X position, 1 byte for Y position,
 // 1 byte for wheel motion
 #define SC_HID_MOUSE_INPUT_SIZE 4

app/src/hid/hid_mouse.h

@@ -3,8 +3,6 @@
 
 #include "common.h"
 
-#include <stdbool.h>
-
 #include "hid/hid_event.h"
 #include "input_events.h"