Add a config.mk file where global variables can be modified, add aarch64

interrupts with IRQ and syscalls, make phys_to_virt checked, recreate
stack on aarch64, make serial console finally line wrap and have max
height correctly, add U64Buf for when i need number debug, rename mouse
and keyboard files to kmi and merge them, add non-working pl050 support

kernel/src/config.rs

@@ -0,0 +1 @@
+pub const TIMER_FREQUENCY_HZ: usize = 1000;