[POWERPC] 4xx: Add NOR FLASH entries to Canyonlands and Glacier dts

This patch adds default NOR entries to the AMCC Canyonlands (460EX)
and Glacier (460GT) dts files.

Signed-off-by: Stefan Roese <sr@denx.de>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>