Make NKPT a kernel option on i386 so that it can be set to a non-default

value from kernel config files.

Tested by:	Charles Sprickman  spork of bway net
MFC after:	2 weeks

sys/conf/options.i386

@@ -12,6 +12,7 @@ I586_PMC_GUPROF		opt_i586_guprof.h
 MAXMEM
 MPTABLE_FORCE_HTT
 MP_WATCHDOG
+NKPT			opt_pmap.h
 PERFMON
 PMAP_SHPGPERPROC	opt_pmap.h
 POWERFAIL_NMI		opt_trap.h

sys/i386/conf/NOTES

@@ -862,6 +862,15 @@ options 	PMAP_SHPGPERPROC=201
 #
 options 	KVA_PAGES=260
 
+#
+# Number of initial kernel page table pages used for early bootstrap.
+# This number should include enough pages to map the kernel, any
+# modules or other data loaded with the kernel by the loader, and data
+# structures allocated before the VM system is initialized such as the
+# vm_page_t array.  Each page table page maps 4MB (2MB with PAE).
+#
+options 	NKPT=31
+
 
 #####################################################################
 # ABI Emulation

sys/i386/i386/mp_machdep.c

@@ -30,6 +30,7 @@ __FBSDID("$FreeBSD$");
 #include "opt_cpu.h"
 #include "opt_kstack_pages.h"
 #include "opt_mp_watchdog.h"
+#include "opt_pmap.h"
 #include "opt_sched.h"
 #include "opt_smp.h"
 

sys/i386/xen/mp_machdep.c

@@ -31,6 +31,7 @@ __FBSDID("$FreeBSD$");
 #include "opt_cpu.h"
 #include "opt_kstack_pages.h"
 #include "opt_mp_watchdog.h"
+#include "opt_pmap.h"
 #include "opt_sched.h"
 #include "opt_smp.h"