x86_64: add drivers for Xeon controller hub based GPIO

These drivers are in many reference-design Xeon, iCore, or
Atom64 based server boards.

Signed-off-by: Philip Prindeville <philipp@redfish-solutions.com>

target/linux/x86/64/config-default

@@ -136,8 +136,10 @@ CONFIG_GPIOLIB=y
 CONFIG_GPIO_ACPI=y
 # CONFIG_GPIO_AMDPT is not set
 # CONFIG_GPIO_F7188X is not set
-# CONFIG_GPIO_IT87 is not set
-# CONFIG_GPIO_LYNXPOINT is not set
+CONFIG_GPIO_ICH=y
+CONFIG_GPIO_IT87=y
+CONFIG_GPIO_LYNXPOINT=y
+CONFIG_GPIO_SCH=y
 CONFIG_GPIO_SYSFS=y
 CONFIG_HAVE_ACPI_APEI=y
 CONFIG_HAVE_ACPI_APEI_NMI=y