Explicitly reset static variables device_type and first_run in
retro_deinit() and retro_init() to guarantee a clean state when
the core is reloaded. This fixes input descriptors not refreshing
after core reloads due to retained static values.

• Reset device_type to {-1, -1, -1, -1 in retro_deinit()
• Ensure first_run is reinitialized to true in retro_init()
• Addresses platform-specific behavior where dynamic libraries may retain
  static variables even after unload (e.g., incomplete OS-level cleanup)