Drop Kconfig variable BOARD_HAS_HARD_RESET

hard_reset was indeed consolidated and moved into the southbridge
code a while ago, but the config variable was still kept alife, with
some duplicate code.

Change-Id: I60d4a87de916667f6e89353dfbe1a7b9eca380f7
Signed-off-by: Stefan Reinauer <reinauer@google.com>
Reviewed-on: http://review.coreboot.org/1837
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>

src/mainboard/intel/xe7501devkit/Kconfig

@@ -9,7 +9,6 @@ config BOARD_SPECIFIC_OPTIONS # dummy
 	select SOUTHBRIDGE_INTEL_I82801CX
 	select SUPERIO_SMSC_LPC47B272
 	select ROMCC
-	select BOARD_HAS_HARD_RESET
 	select HAVE_PIRQ_TABLE
 	select HAVE_MP_TABLE
 	select UDELAY_TSC