Replace SDL types by C99 standard types

Scrcpy is a C11 project. Use the C99 standard types instead of the
SDL-specific types:

    SDL_bool -> bool
    SintXX   -> intXX_t
    UintXX   -> uintXX_t

app/src/device.h

@@ -1,7 +1,7 @@
 #ifndef DEVICE_H
 #define DEVICE_H
 
-#include <SDL2/SDL_stdinc.h>
+#include <stdbool.h>
 
 #include "common.h"
 #include "net.h"
@@ -10,7 +10,7 @@
 #define DEVICE_SDCARD_PATH "/sdcard/"
 
 // name must be at least DEVICE_NAME_FIELD_LENGTH bytes
-SDL_bool
+bool
 device_read_info(socket_t device_socket, char *name, struct size *frame_size);
 
 #endif