sam460ex: Update u-boot-sam460ex firmware

Update the submodule and u-boot-sam460-20100605.bin to include
following fixes from Sebastian Bauer:
- Fix build with newer gcc
- Decrease unnecessary delay which fixes slow booting from CD

Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

roms/u-boot-sam460ex

@@ -1 +1 @@
-Subproject commit 8ee007c4216fd6a0d760589e8405ce4494497aa0
+Subproject commit 60b3916f33e617a815973c5a6df77055b2e3a588