Use a suitable code generation when building libstand for MIPS.

Reviewed by:	imp
Sponsored by:	DARPA, AFRL
MFC after:	3 days
Also call configtest before reload to ensure working config.

Approved by:	jhb
MFC after:	1 week
X-MFC-With:	r249489
Partial MFP4 of 222836:

Only look for FDT partitions if our potential parent is a DISK device.

Excluding direct recursion on the flashmap geoms was insufficient
because it did not prevent the underlying device from being retrieved if
flashmap geoms were further partitioned.

Reviewed by:	imp
Sponsored by:	DARPA, AFRL