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/cpu/intel_common/Makefile b/arch/x86/cpu/intel_common/Makefile
index e22c707..1736bd2 100644
--- a/arch/x86/cpu/intel_common/Makefile
+++ b/arch/x86/cpu/intel_common/Makefile
@@ -28,6 +28,7 @@
 endif
 obj-y += pch.o
 obj-$(CONFIG_HAVE_ITSS) += itss.o
+obj-$(CONFIG_HAVE_P2SB) += p2sb.o
 
 ifdef CONFIG_SPL
 ifndef CONFIG_SPL_BUILD