Add routine for 32bit print.
user
```assembly
; =============================================================================
; Copyright (C) 2015 Manolis Fragkiskos Ragkousis -- see LICENSE.TXT
; =============================================================================

;;; Print routine
;;; ebx contains a null terminated string

%ifndef PRINT_STRING_PM
%define PRINT_STRING_PM

[bits 32]
VIDEO_MEMORY equ 0xb8000
WHITE_ON_BLACK equ 0x0f
        
print_string_pm:
        pusha
        mov edx, VIDEO_MEMORY

print_string_pm_loop:
        mov al, [ebx]
        mov ah, WHITE_ON_BLACK

        cmp al, 0
        je print_string_pm_done

        mov [edx], ax
        add ebx, 1
        add edx, 2

        jmp print_string_pm_loop

print_string_pm_done:   
        popa
        ret
        
%endif
```
assistant