inteltool: add --ahci for printing AHCI registers

According to datasheets for Intel ICH/PCH, it works for chipsets from
ICH7 to 9-series PCH, with PCI device address D31:F2.

Change-Id: If1ddd7208108bda949b5a94894a7bf9e8bfe1e5f
Signed-off-by: Iru Cai <mytbk920423@gmail.com>
Reviewed-on: https://review.coreboot.org/15106
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>

util/inteltool/Makefile

@@ -23,7 +23,7 @@ PREFIX  ?= /usr/local
 CFLAGS  ?= -O2 -g -Wall -W
 LDFLAGS += -lpci -lz
 
-OBJS = inteltool.o cpu.o gpio.o rootcmplx.o powermgt.o memory.o pcie.o amb.o ivy_memory.o spi.o gfx.o
+OBJS = inteltool.o cpu.o gpio.o rootcmplx.o powermgt.o memory.o pcie.o amb.o ivy_memory.o spi.o gfx.o ahci.o
 
 OS_ARCH	= $(shell uname)
 ifeq ($(OS_ARCH), Darwin)