Kernel/Userspace: Replace my custom SHM system with SysV shm

This allows xbanan to use shm!

userspace/libraries/LibC/include/sys/banan-os.h

@@ -43,13 +43,6 @@ int poweroff(int command);
 
 int load_keymap(const char* path);
 
-// Create shared memory object and return its key or -1 on error
-long smo_create(size_t size, int prot);
-// Delete shared memory object such that it will be no longer accessible with smo_map(). Existing mappings are still valid
-int smo_delete(long key);
-// Map shared memory object defined by its key and return address or null on error. Mappings can be unmapped using munmap()
-void* smo_map(long key);
-
 __END_DECLS
 
 #endif