hwmon: (it87) Support for 16-bit fan reading in it8712 >= rev 0x07

The it8712 chip supports 16-bit fan tachometers in revisions >= 0x07.
Revisions >= 0x08 dropped support for 8-bit fan divisor registers. The
patch enables 16-bit fan readings on all revisions >= 0x07 just like
the it8716 and it8718 chips.

Signed-off-by: Andrew Paprocki <andrew@ishiboo.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

Documentation/hwmon/it87

@@ -11,7 +11,9 @@ Supported chips:
     Prefix: 'it8712'
     Addresses scanned: from Super I/O config space (8 I/O ports)
     Datasheet: Publicly available at the ITE website
-               http://www.ite.com.tw/
+               http://www.ite.com.tw/product_info/file/pc/IT8712F_V0.9.1.pdf
+               http://www.ite.com.tw/product_info/file/pc/Errata%20V0.1%20for%20IT8712F%20V0.9.1.pdf
+               http://www.ite.com.tw/product_info/file/pc/IT8712F_V0.9.3.pdf
   * IT8716F/IT8726F
     Prefix: 'it8716'
     Addresses scanned: from Super I/O config space (8 I/O ports)
@@ -90,14 +92,13 @@ upper VID bits share their pins with voltage inputs (in5 and in6) so you
 can't have both on a given board.
 
 The IT8716F, IT8718F and later IT8712F revisions have support for
-2 additional fans. They are supported by the driver for the IT8716F and
-IT8718F but not for the IT8712F
+2 additional fans. The additional fans are supported by the driver.
 
 The IT8716F and IT8718F, and late IT8712F and IT8705F also have optional
 16-bit tachometer counters for fans 1 to 3. This is better (no more fan
 clock divider mess) but not compatible with the older chips and
 revisions. For now, the driver only uses the 16-bit mode on the
-IT8716F and IT8718F.
+late IT8712F, IT8716F and IT8718F.
 
 The IT8726F is just bit enhanced IT8716F with additional hardware
 for AMD power sequencing. Therefore the chip will appear as IT8716F