Added a os_upper_case function

source/kernel/features/utils.asm

@@ -0,0 +1,18 @@
+; Outputs the contents of a file
+util_cat:
+   pusha
+
+   call os_print_newline
+
+   mov si, cat_prompt
+   call os_print_string
+
+   mov ax, 11 ; length of input
+   mov di, user_input
+
+   popa
+   ret
+
+
+section .data:
+   cat_prompt db 'Enter file name: ', 0