lib: create common ascii hex array

Add a common hex array in hexdump.c so everyone can use it.

Add a common hi/lo helper to avoid the shifting masking that is
done to get the upper and lower nibbles of a byte value.

Pull the pack_hex_byte helper from kgdb as it is opencoded many
places in the tree that will be consolidated.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/kgdb.c

@@ -346,14 +346,6 @@ static void put_packet(char *buffer)
 	}
 }
 
-static char *pack_hex_byte(char *pkt, u8 byte)
-{
-	*pkt++ = hexchars[byte >> 4];
-	*pkt++ = hexchars[byte & 0xf];
-
-	return pkt;
-}
-
 /*
  * Convert the memory pointed to by mem into hex, placing result in buf.
  * Return a pointer to the last char put in buf (null). May return an error.