Implement hcall based RTAS for pSeries machines

On pSeries machines, operating systems can instantiate "RTAS" (Run-Time
Abstraction Services), a runtime component of the firmware which implements
a number of low-level, infrequently used operations.  On logical partitions
under a hypervisor, many of the RTAS functions require hypervisor
privilege.  For simplicity, therefore, hypervisor systems typically
implement the in-partition RTAS as just a tiny wrapper around a hypercall
which actually implements the various RTAS functions.

This patch implements such a hypercall based RTAS for our emulated pSeries
machine.  A tiny in-partition "firmware" calls a new hypercall, which
looks up available RTAS services in a table.

Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/Makefile b/Makefile
index 89e88b4..e0b3fea 100644
--- a/Makefile
+++ b/Makefile
@@ -213,7 +213,8 @@
 pxe-rtl8139.bin pxe-virtio.bin \
 bamboo.dtb petalogix-s3adsp1800.dtb petalogix-ml605.dtb \
 multiboot.bin linuxboot.bin \
-s390-zipl.rom
+s390-zipl.rom \
+spapr-rtas.bin
 else
 BLOBS=
 endif