ARM: at91: code removal of CAP9 SoC

Following removal announce and addition to feature-removal-schedule.txt,
here is the actual source code deletion for Atmel CAP9 family.

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>