ipro1000: Always use DELAY() for microsecond pauses (on Haiku.)

pause() has granularity of "hz", which on FreeBSD and in our compat layer
is defined to be 1000 (so, 1ms.) As "safe_pause_us" is used copoiously
throughout startup code, this meant that (1) startup takes 100-1000x longer
than it needed to (this driver seems to most commonly delay for 10us),
and (2) this could in theory block the boot for multiple minutes if one
got particularly unlucky with the scheduler.

Probably helps with or even outright fixes #14795.

src/add-ons/kernel/drivers/network/ipro1000/dev/e1000/e1000_osdep.h

@@ -83,11 +83,15 @@ ms_scale(int x) {
 
 static inline void
 safe_pause_us(int x) {
+#ifndef __HAIKU__
 	if (cold) {
 		DELAY(x);
 	} else {
 		pause("e1000_delay", max(1,  x/(1000000/hz)));
 	}
+#else
+	DELAY(x);
+#endif
 }
 
 static inline void