hdata: Fix SP attention area address
hdata: Fix SP attention area address

SP attention area is aligned. We were sending wrong address.
Hence `attn` on FSP based system is failing. Align SP attention
area so that FSP can locate attention data.

Fixes: 518e554 (spira: fix endian conversions in spira data structures)
CC: Nicholas Piggin <npiggin@gmail.com>

Signed-off-by: Vasant Hegde <a6d753843573f7bfed5075c1e875b0be8007a0ab@linux.vnet.ibm.com>
Signed-off-by: Oliver O'Halloran <3dfaff8fa6ae977f042064a112a6aac576279b9b@gmail.com>

legoater/skiboot,legoater/skiboot,shenki/skiboot,open-power/skiboot,open-power/skiboot,legoater/skiboot,shenki/skiboot,open-power/skiboot,qemu/skiboot,qemu/skiboot,qemu/skiboot,shenki/skiboot,shenki/skiboot,open-power/skiboot,legoater/skiboot,qemu/skiboot,legoater/skiboot,qemu/skiboot,shenki/skiboot,open-power/skiboot