doc: small kernel-parameters updates

Change last "i386" to X86-32 as is used throughout the rest of the file.
Change combination of X86-32,X86-64 to just X86, as is done throughout the
rest of the file.

Add a note that hyphens and underscores are equivalent in parameter names,
with examples.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Jan Engelhardt <jengelh@medozas.de>
Cc: Christopher Sylvain <chris.sylvain@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Documentation/kernel-parameters.txt

@@ -17,6 +17,12 @@ are specified on the kernel command line with the module name plus
 
 	usbcore.blinkenlights=1
 
+Hyphens (dashes) and underscores are equivalent in parameter names, so
+	log_buf_len=1M print-fatal-signals=1
+can also be entered as
+	log-buf-len=1M print_fatal_signals=1
+
+
 This document may not be entirely up to date and comprehensive. The command
 "modinfo -p ${modulename}" shows a current list of all parameters of a loadable
 module. Loadable modules, after being loaded into the running kernel, also
@@ -345,7 +351,7 @@ and is between 256 and 4096 characters. It is defined in the file
 			not play well with APC CPU idle - disable it if you have
 			APC and your system crashes randomly.
 
-	apic=		[APIC,i386] Advanced Programmable Interrupt Controller
+	apic=		[APIC,X86-32] Advanced Programmable Interrupt Controller
 			Change the output verbosity whilst booting
 			Format: { quiet (default) | verbose | debug }
 			Change the amount of debugging information output
@@ -702,7 +708,7 @@ and is between 256 and 4096 characters. It is defined in the file
 			to discrete, to make X server driver able to add WB
 			entry later. This parameter enables that.
 
-	enable_timer_pin_1 [i386,x86-64]
+	enable_timer_pin_1 [X86]
 			Enable PIN 1 of APIC timer
 			Can be useful to work around chipset bugs
 			(in particular on some ATI chipsets).