mpc8308: Migrate system io config to Kconfig

Migrate the system IO configuration setting to Kconfig.

Signed-off-by: Mario Six <mario.six@gdsys.cc>
diff --git a/configs/MPC8308RDB_defconfig b/configs/MPC8308RDB_defconfig
index e674848..9be5155 100644
--- a/configs/MPC8308RDB_defconfig
+++ b/configs/MPC8308RDB_defconfig
@@ -62,6 +62,14 @@
 CONFIG_HID0_FINAL_DPM=y
 CONFIG_HID0_FINAL_ICE=y
 CONFIG_HID2_HBE=y
+CONFIG_SICR_ETSEC1_A_TSEC_GTX_CLK125=y
+CONFIG_SICR_GPIO_A_TSEC2=y
+CONFIG_SICR_GPIO_B_TSEC_GTX_CLK125=y
+CONFIG_SICR_IEEE1588_A_GPIO=y
+CONFIG_SICR_GTM_GPIO=y
+CONFIG_SICR_GPIOSEL_IEEE1588=y
+CONFIG_SICR_TMSOBI1_2_5_V=y
+CONFIG_SICR_TMSOBI2_2_5_V=y
 CONFIG_FIT=y
 CONFIG_FIT_VERBOSE=y
 CONFIG_OF_BOARD_SETUP=y