ISAPNP: handle independent options following dependent ones

The ISAPNP spec recommends that independent options precede
dependent ones, but this is not actually required.  The current
ISAPNP code incorrectly puts such trailing independent options
at the end of the last dependent option list.

This patch fixes that bug by resetting the current option list
to the independent list when we see an "End Dependent Functions"
tag.  PNPBIOS and PNPACPI handle this the same way.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Rene Herman <rene.herman@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>