x86: tangier: kconfig: Guard tangier-specific options

These options should not be exposed to other platforms.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
diff --git a/arch/x86/cpu/tangier/Kconfig b/arch/x86/cpu/tangier/Kconfig
index 86a3340..2469b1e 100644
--- a/arch/x86/cpu/tangier/Kconfig
+++ b/arch/x86/cpu/tangier/Kconfig
@@ -16,6 +16,8 @@
 	imply USB
 	imply USB_DWC3
 
+if INTEL_TANGIER
+
 config SYS_CAR_ADDR
 	hex
 	default 0x19200000
@@ -30,3 +32,5 @@
 config SYS_USB_OTG_BASE
 	hex
 	default 0xf9100000
+
+endif