package/freerdp: move architecture-specific block

Move the arch-spcific block up, so it does not interfere with followup
patches (mostly to ease review).

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Reviewed-by: Samuel Martin <s.martin49@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>