- made improvements to memory code (refactored)

- started on improvements to the page frame allocator. it should be able to provide a usable page for any given virtual memory address requested.

kernel/src/arch/x86_64/cpu/apic.rs

@@ -1,6 +1,6 @@
 use core::arch::x86_64::__cpuid;
 
-use crate::arch::x86_64::memory::memory_map::PHYSICAL_MEMORY_OFFSET;
+use crate::arch::x86_64::memory::mapping::PHYSICAL_MEMORY_OFFSET;
 use crate::serial_print;
 use x86_64::{
     PhysAddr, VirtAddr,