Pull up following revision(s) (requested by tsutsui in ticket #1445):

sys/arch/arm/sa11x0/sa11x0_ost.c: revision 1.33

Fix another attach failure of zaudio(4) WM8731 on Zaurus SL-C7x0/860.

When kernels were configured for both CPU_XSCALE_PXA270 and
CPU_XSCALE_PXA250, the OST freq value was not set until tc_init(9)
then all delay(9) during configure(9) returned immediately.

While here, use proper macro with description for readability.

Should be pulled up to netbsd-8 and netbsd-9.
(though zaudio(4) won't work on netbsd-8)

(martin)