swap sys/param.h for machine/param.h. this still obtains the

wanted COHERENCY_UNIT, while avoiding have a cascade of
failures where sys/mutex.h ends up including arm/cpu.h which
ends up including sys/resourcevar.h and then sys/mutex.h,
but as the first includer of sys/mutex.h has defined the
idempotent header define, the second one is empty, and as
kmutex_t isn't defined by the first attempt yet the kmutex_t
used in resourcevar.h generates an error.

should fix evbarm v5/v5eb, hpcarm, iyonix and zaurus builds.

tested building iyonix, zaurus and evbarmv7hf.

sys/arch/arm/include/cpu.h

@@ -1,4 +1,4 @@
-/*	$NetBSD: cpu.h,v 1.113 2020/08/16 16:01:35 skrll Exp $	*/
+/*	$NetBSD: cpu.h,v 1.114 2020/08/17 01:52:59 mrg Exp $	*/
 
 /*
  * Copyright (c) 1994-1996 Mark Brinicombe.
@@ -154,7 +154,7 @@ static inline void cpu_dosoftints(void);
 #include <sys/cpu_data.h>
 #include <sys/device_if.h>
 #include <sys/evcnt.h>
-#include <sys/param.h>
+#include <machine/param.h>
 
 struct cpu_info {
 	struct cpu_data	ci_data;	/* MI per-cpu data */