at91rm9200: introduce at91rm9200_set_type to specficy cpu package

as we can not detect it
by defaut the type will be bga
introduce cpu_is_at91rm9200_bga and cpu_is_at91rm9200_pqfp

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Patrice Vilchez <patrice.vilchez@atmel.com>