hpet: common ACPI generation

HPET's min ticks (minimum time between events to avoid
losing interrupts) is chipset specific, so move it to
Kconfig.

Via also has a special base address, so move it as well.

Apart from these (and the base address was already #defined),
the table is very uniform.

Change-Id: I848a2e2b0b16021c7ee5ba99097fa6a5886c3286
Signed-off-by: Patrick Georgi <patrick@georgi-clan.de>
Reviewed-on: http://review.coreboot.org/1562
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Reviewed-by: Dave Frodin <dave.frodin@se-eng.com>
diff --git a/src/mainboard/samsung/stumpy/romstage.c b/src/mainboard/samsung/stumpy/romstage.c
index 58305c8..5602c63 100644
--- a/src/mainboard/samsung/stumpy/romstage.c
+++ b/src/mainboard/samsung/stumpy/romstage.c
@@ -190,7 +190,7 @@
 		smbusbar: SMBUS_IO_BASE,
 		wdbbar: 0x4000000,
 		wdbsize: 0x1000,
-		hpet_address: HPET_ADDR,
+		hpet_address: CONFIG_HPET_ADDRESS,
 		rcba: DEFAULT_RCBABASE,
 		pmbase: DEFAULT_PMBASE,
 		gpiobase: DEFAULT_GPIOBASE,