soc/intel/apollolake: Add utility functions for global reset

Apollolake defines Global Reset where Host, TXE and PMC are reset.
During boot we may need to trigger a global reset as part of platform
initialization (or for error handling). Add functions to trigger
global reset, enable/disable it and lock global reset bit.

BUG=chrome-os-partner:54149
BRANCH=none
TEST=none

Change-Id: I84296cd1560a0740f33ef6b488f15f99d397998d
Signed-off-by: Andrey Petrov <andrey.petrov@intel.com>
Reviewed-on: https://review.coreboot.org/15198
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

src/soc/intel/apollolake/Makefile.inc

@@ -29,6 +29,7 @@ romstage-y += meminit.c
 romstage-y += mmap_boot.c
 romstage-y += tsc_freq.c
 romstage-y += pmutil.c
+romstage-y += reset.c
 romstage-y += spi.c
 
 smm-y += mmap_boot.c
@@ -54,6 +55,7 @@ ramstage-y += spi.c
 ramstage-y += tsc_freq.c
 ramstage-y += pmutil.c
 ramstage-y += pmc.c
+ramstage-y += reset.c
 ramstage-y += smi.c
 ramstage-y += spi.c
 
@@ -70,6 +72,7 @@ verstage-y += mmap_boot.c
 verstage-$(CONFIG_SOC_UART_DEBUG) += uart_early.c
 verstage-y += tsc_freq.c
 verstage-y += pmutil.c
+verstage-y += reset.c
 verstage-y += spi.c
 
 CPPFLAGS_common += -I$(src)/soc/intel/apollolake/include