Pull up following revision(s) (requested by tsutsui in ticket #1689):

sys/arch/hppa/dev/sti_sgc.c: revision 1.3

Fix silent freeze on probing sti(4) framebuffer on 712/60.  PR/52162

Ok'ed by skrll@.
Should be pulled up to netbsd-9 and netbsd-8.

(martin)