slippy/falco: Re-enable EC software sync

The EC was disabling flash commands and sysjump was not working
properly.  With those two fixed software sync works properly.

BUG=chrome-os-partner:19366
BRANCH=none
TEST=boot with updated EC to test software sync

Google Chrome EC MKBP driver ready, id 'slippy_no_version'
Clearing the recovery request.
EC hash:7fea29992ef72e3e64d8ffe522aa1dfa68dcb44a2da96a4c19530ea1a0bd22c4
EC-RW hash address, size are 0xffa1cfe8, 32.
Hash = 727e79934d9394184da496cebc27f7275b9d2d91079bf125d8f977a1f8aa4cde
Expected hash:727e79934d9394184da496cebc27f7275b9d2d91079bf125d8f977a1f8aa4cde
EC-RW firmware address, size are 0xffad000c, 57180.
VbEcSoftwareSync() - expected len = 57180
Computed hash of expected image:727e79934d9394184da496cebc27f7275b9d2d91079bf125d8f977a1f8aa4cde
VbEcSoftwareSync() updating EC-RW...
VbEcSoftwareSync() jumping to EC-RW
VbEcSoftwareSync() in RW; done

Change-Id: I63ca00d6c94854f2b395eb736ce20792da5f8de2
Signed-off-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/56821

src/mainboard/google/falco/Kconfig

@@ -9,6 +9,7 @@ config BOARD_SPECIFIC_OPTIONS # dummy
 	select INTEL_LYNXPOINT_LP
 	select BOARD_ROMSIZE_KB_8192
 	select EC_GOOGLE_CHROMEEC
+	select EC_SOFTWARE_SYNC
 	select HAVE_ACPI_TABLES
 	select HAVE_OPTION_TABLE
 	select HAVE_ACPI_RESUME

src/mainboard/google/slippy/Kconfig

@@ -9,6 +9,7 @@ config BOARD_SPECIFIC_OPTIONS # dummy
 	select INTEL_LYNXPOINT_LP
 	select BOARD_ROMSIZE_KB_8192
 	select EC_GOOGLE_CHROMEEC
+	select EC_SOFTWARE_SYNC
 	select HAVE_ACPI_TABLES
 	select HAVE_OPTION_TABLE
 	select HAVE_ACPI_RESUME