MIPS: Alchemy: Change strict_strtol to strict_strtoul

Since memsize is unsigned, it would seem better to use strict_strtoul that
strict_strtol.

A simplified version of the semantic patch that makes this change is as
follows: (http://www.emn.fr/x-info/coccinelle/

)

// <smpl>
@s2@
long e;
position p;
@@

strict_strtol@p(...,&e)

@@
position p != s2.p;
type T;
T e;
@@

- strict_strtol@p
+ strict_strtoul
  (...,&e)
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>