feature(xen): dynamic platform architecture (#194)

* wip hvm

* feat: move platform stuff all into it's own thing

* hvm work

* more hvm work

* more hvm work

* feat: rework to support multiple platforms

* hvm nonredist

* more hvm work

* more hvm work

* pvh work

* work on loading cmdline

* implement initrd loading for pvh

* partially working pvh support

* fix merge issues

* pvh works!

* swap over to pv support

* remove old kernel stuff

* fix support for pv

* pvh is gone for now

* fix(runtime): debug should be respected

* fix(xen): arm64 is currently unsupported, treat it as such at runtime

* fix(examples): use architecture cfg for boot example

* fix(x86): use IOMMU only when needed for passthrough

* chore(build): print kernel architecture during fetch

os/internal/stage1.sh

@@ -16,10 +16,7 @@ done
 
 apk add xen xen-hypervisor
 
-for SERVICE in xenconsoled xenstored
-do
-  rc-update add "${SERVICE}" default
-done
+rc-update add xenstored default
 
 for MODULE in xen-netblock xen-blkback tun tap
 do