kernel: Remove unnecessary includes

Removes unnecessary direct dependencies in some headers and also gets
rid of indirect dependencies that were being relied on to be included.

src/core/hle/kernel/hle_ipc.cpp

@@ -2,6 +2,7 @@
 // Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
+#include <algorithm>
 #include <utility>
 
 #include <boost/range/algorithm_ext/erase.hpp>