hwmon: (it87) request only Environment Controller ports

The IT8705F and related parts are Super I/O controllers that contain
many separate devices.

Some BIOSes describe IT8705F I/O port usage under a motherboard device
(PNP0C02) with overlapping regions, e.g., 0x290-0x29f and 0x290-0x294.

The it87 driver supports only the Environment Controller, which requires
only two ISA ports, but it used to request an eight-port range.  If that
range exceeds a range reported by the BIOS, as 0x290-0x297 would, the
request fails, and the it87 driver cannot claim the device.

This patch makes the it87 driver request only the two ports used for the
Environment Controller device.

Systems where this problem has been reported:
    Gigabyte GA-K8N Ultra 9
    Gigabyte M56S-S3
    Gigabyte GA-965G-DS3

Kernel bug reports:
    http://bugzilla.kernel.org/show_bug.cgi?id=9514
    http://lkml.org/lkml/2007/12/4/466

Related change:
    http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=a7839e96...