sys: Implement LAPIC and IOAPIC support, add PS/2 keyboard driver

- Added LAPIC implementation in `apic.c` and `apic.h`, including initialization and basic operations.
- Introduced IOAPIC (I/O Advanced Programmable Interrupt Controller) support in `ioapic.c` and `ioapic.h`, parsing the ACPI MADT to locate IOAPICs and manage redirection entries.
- Implemented PS/2 keyboard driver in `ps2.c` and `ps2.h`, handling keyboard interrupts and translating scancodes to ASCII.
- Attempted to make usermode work again (it failed, coming soon)
- Cleaned up comments in `time.c` and `render.c` for clarity.

Signed-off-by: kaguya <vpshinomiya@protonmail.com>

src/syscall/syscall_entry.S

@@ -3,8 +3,10 @@
 syscall_entry:
     swapgs
 
-    push %rcx
-    push %r11
+    mov %rsp, %gs:0x10 # save user rsp for per cpu
+
+    push %rcx # save user rip
+    push %r11 # save rflags
 
     # Save original args before we clobber them
     push %rdi        # orig rdi (arg1)