x86: Move P2SB from Apollo Lake to a more generic location

The Primary to Sideband Bridge (P2SB) is not specific to Apollo Lake, so
move its driver to a common location within arch/x86.

Signed-off-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index b733d22..b3fbf30 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -715,6 +715,13 @@
 	  Select this to include the driver for the Interrupt Timer
 	  Subsystem (ITSS) which is found on several Intel devices.
 
+config HAVE_P2SB
+	bool "Enable P2SB"
+	help
+	  Select this to include the driver for the Primary to
+	  Sideband Bridge (P2SB) which is found on several Intel
+	  devices.
+
 menu "System tables"
 	depends on !EFI && !SYS_COREBOOT