mpc83xx: Migrate SPCR to Kconfig

Migrate the SPCR setting to Kconfig.

Signed-off-by: Mario Six <mario.six@gdsys.cc>
diff --git a/configs/MPC8323ERDB_defconfig b/configs/MPC8323ERDB_defconfig
index b52d1fd..08486f8 100644
--- a/configs/MPC8323ERDB_defconfig
+++ b/configs/MPC8323ERDB_defconfig
@@ -75,6 +75,7 @@
 CONFIG_HID2_HBE=y
 CONFIG_ACR_PIPE_DEP_4=y
 CONFIG_ACR_RPTCNT_4=y
+CONFIG_SPCR_OPT_SPEC_READ=y
 CONFIG_OF_BOARD_SETUP=y
 CONFIG_OF_STDOUT_VIA_ALIAS=y
 CONFIG_BOOTDELAY=6