x86: add another PCI ID for ICH6 force hpet.

Tested on Asus P5GDC-V

$ lspci -n -n |grep ISA
00:1f.0 ISA bridge [0601]: Intel Corporation 82801FB/FR (ICH6/ICH6R) LPC Interface Bridge [8086:2640] (rev 03)

Force enabled HPET at base address 0xfed00000
hpet clockevent registered
hpet0: at MMIO 0xfed00000, IRQs 2, 8, 0
hpet0: 3 64-bit timers, 14318180 Hz

Signed-off-by: Krzysztof Piotr Oledzki <ole@ans.pl>
Cc: mingo@elte.hu
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>