mpc83xx: Introduce ARCH_MPC830*

Replace CONFIG_MPC830* with proper CONFIG_ARCH_MPC830* Kconfig options.

Signed-off-by: Mario Six <mario.six@gdsys.cc>
diff --git a/drivers/ram/mpc83xx_sdram.c b/drivers/ram/mpc83xx_sdram.c
index 441baeb..e352329 100644
--- a/drivers/ram/mpc83xx_sdram.c
+++ b/drivers/ram/mpc83xx_sdram.c
@@ -179,7 +179,7 @@
 	case ODT_RD_NEVER:
 	case ODT_RD_ONLY_CURRENT:
 	case ODT_RD_ONLY_OTHER_CS:
-		if (!IS_ENABLED(CONFIG_MPC830x) &&
+		if (!IS_ENABLED(CONFIG_ARCH_MPC830X) &&
 		    !IS_ENABLED(CONFIG_MPC831x) &&
 		    !IS_ENABLED(CONFIG_MPC8360) &&
 		    !IS_ENABLED(CONFIG_MPC837x)) {
@@ -210,7 +210,7 @@
 	case ODT_WR_NEVER:
 	case ODT_WR_ONLY_CURRENT:
 	case ODT_WR_ONLY_OTHER_CS:
-		if (!IS_ENABLED(CONFIG_MPC830x) &&
+		if (!IS_ENABLED(CONFIG_ARCH_MPC830X) &&
 		    !IS_ENABLED(CONFIG_MPC831x) &&
 		    !IS_ENABLED(CONFIG_MPC8360) &&
 		    !IS_ENABLED(CONFIG_MPC837x)) {