Export new PACA constants in asm-offsets

In order to access fields in the PACA from assembly code, we need
to generate offsets using asm-offsets.c.

So let's add the new PACA related bits, we just introduced!

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>