several evbarm kernels broken in current. know the issue. don't know how best to fix it.

["Martin Fouts" <fouts%fogey.com@localhost>]

I'm getting ready to port NetBSD to another ARM device (personal, not for my
employer,) and I tried to make a release in current in preparation. This did
not go so well, as there's build breakage in may of the evbarm kernels.  In
outline, the problem is that sys/device.h includes some other include file
that starts an include chain that ends up with an include file that uses
things defined later in sys/device.h.  The clearest example is:

In file included from
/home/marty/projects/netbsd/current/src/sys/arch/evbarm/ifpga/ifpga_intr.h:5
0,
                 from ./machine/intr.h:151,
                 from
/home/marty/projects/netbsd/current/src/sys/sys/intr.h:35,
                 from
/home/marty/projects/netbsd/current/src/sys/sys/mutex.h:177,
                 from
/home/marty/projects/netbsd/current/src/sys/sys/device.h:85,
                 from ./arm/cpu.h:233,
                 from ./machine/cpu.h:3,
                 from ./arm/arm32/param.h:39,
                 from ./machine/param.h:45,
                 from
/home/marty/projects/netbsd/current/src/sys/sys/param.h:164,
                 from /tmp/genassym.27565/assym.c:2:
/home/marty/projects/netbsd/current/src/sys/arch/evbarm/ifpga/ifpgavar.h:48:
error: field 'sc_dev' has incomplete type

To make a long story short, 'sc_dev is declared as 'struct device sc_dev';
but mutex.h is included in device.h before device.h defines struct device.

Any thoughts on the cleanest way to fix this and related arm kernel
breakages?