x86, msr: Export the register-setting MSR functions via /dev/*/msr

Make it possible to access the all-register-setting/getting MSR
functions via the MSR driver.  This is implemented as an ioctl() on
the standard MSR device node.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Borislav Petkov <petkovbb@gmail.com>
diff --git a/Documentation/ioctl/ioctl-number.txt b/Documentation/ioctl/ioctl-number.txt
index dbea4f9..1c058b5 100644
--- a/Documentation/ioctl/ioctl-number.txt
+++ b/Documentation/ioctl/ioctl-number.txt
@@ -121,6 +121,7 @@
 'c'	00-7F	linux/comstats.h	conflict!
 'c'	00-7F	linux/coda.h		conflict!
 'c'	80-9F	arch/s390/include/asm/chsc.h
+'c'	A0-AF   arch/x86/include/asm/msr.h
 'd'	00-FF	linux/char/drm/drm/h	conflict!
 'd'	F0-FF	linux/digi1.h
 'e'	all	linux/digi1.h		conflict!