cs: implement GetFirmwareVersion command

stratosphere/cs/source/cs_main.cpp

@@ -120,6 +120,7 @@ void __appInit(void) {
     lr::Initialize();
     R_ABORT_UNLESS(ldr::InitializeForShell());
     R_ABORT_UNLESS(pgl::Initialize());
+    R_ABORT_UNLESS(setsysInitialize());
     /* TODO: Other services? */
 
     ams::CheckApiVersion();
@@ -127,6 +128,7 @@ void __appInit(void) {
 
 void __appExit(void) {
     /* TODO: Other services? */
+    setsysExit();
     pgl::Finalize();
     ldr::FinalizeForShell();
     lr::Finalize();