powerpc: T4160QDS: Separate from T4240QDS in Kconfig

Use TARGET_T4160QDS to simplify Kconfig options.

Signed-off-by: York Sun <york.sun@nxp.com>
diff --git a/arch/powerpc/cpu/mpc85xx/Kconfig b/arch/powerpc/cpu/mpc85xx/Kconfig
index c1003a3..d0fdceb 100644
--- a/arch/powerpc/cpu/mpc85xx/Kconfig
+++ b/arch/powerpc/cpu/mpc85xx/Kconfig
@@ -260,6 +260,11 @@
 	select SUPPORT_SPL
 	select PHYS_64BIT
 
+config TARGET_T4160QDS
+	bool "Support T4160QDS"
+	select SUPPORT_SPL
+	select PHYS_64BIT
+
 config TARGET_T4240QDS
 	bool "Support T4240QDS"
 	select SUPPORT_SPL
diff --git a/arch/powerpc/cpu/mpc85xx/fsl_corenet2_serdes.c b/arch/powerpc/cpu/mpc85xx/fsl_corenet2_serdes.c
index 810ddb0..587736c 100644
--- a/arch/powerpc/cpu/mpc85xx/fsl_corenet2_serdes.c
+++ b/arch/powerpc/cpu/mpc85xx/fsl_corenet2_serdes.c
@@ -391,7 +391,7 @@
 	case SRDS_PLLCR0_RFCK_SEL_161_13:
 		return "161.1328123";
 	default:
-#if defined(CONFIG_T4240QDS)
+#if defined(CONFIG_T4240QDS) || defined(CONFIG_TARGET_T4160QDS)
 		return "???";
 #else
 		return "122.88";