pull in latest buildrump.sh for makepci
use makepci() to build pci device driver components
support -s alternative_source_tree
fix makelwp signature
accept -q for quiet build (and -qq for even quieter)
add lame workaround for missing pci_user.h when using -s
Nuke unnecessary buildrump.sh invocation.

Probably been unnecessary since we stopped needing multiple source trees.
create test.ffs in makefile instead of buildxen.sh
reorder slightly (for upcoming changes)
beautify/unify buildrump.sh invocations

no functional change
pass extra buildxen parameters to buildrump.sh

e.g. ./buildxen.sh -q -- -V BUILDRUMP_VARIABLE=12765
fix tyop
figure out target machine

also for future unification with baremetal
use common xen/baremetal build script
remove struct schedulable unused members
Implement wall clock time (rumprun-xen issue #13)

This change adds minios_clock_wall() as a global symbol to return wall
clock time from Xen. I did not reinstate the minios "gettime()" which is
available upstream as that relies on a definitition of struct timeval.

minios_monotonic_clock() is renamed to minios_clock_monotonic() for
consistency.

rumpuser_clock_gettime() is updated to support RUMPUSER_CLOCK_REWALL,
returning wall clock time.

All rumphyper calls to the minios NOW() macro are replaced with calls to
the properly namespaces minios_clock_monotonic().

Signed-off-by: Martin Lucina <martin@lucina.net>