mpc83xx: Introduce ARCH_MPC837X

Replace CONFIG_MPC837x with a proper CONFIG_ARCH_MPC837X Kconfig option.

Signed-off-by: Mario Six <mario.six@gdsys.cc>
diff --git a/drivers/ram/mpc83xx_sdram.c b/drivers/ram/mpc83xx_sdram.c
index 3e57b13..f03d042 100644
--- a/drivers/ram/mpc83xx_sdram.c
+++ b/drivers/ram/mpc83xx_sdram.c
@@ -170,7 +170,7 @@
 	switch (odt_rd_cfg) {
 	case ODT_RD_ONLY_OTHER_DIMM:
 		if (!IS_ENABLED(CONFIG_ARCH_MPC8360) &&
-		    !IS_ENABLED(CONFIG_MPC837x)) {
+		    !IS_ENABLED(CONFIG_ARCH_MPC837X)) {
 			debug("%s: odt_rd_cfg value %d invalid.\n",
 			      ofnode_get_name(node), odt_rd_cfg);
 			return -EINVAL;
@@ -182,7 +182,7 @@
 		if (!IS_ENABLED(CONFIG_ARCH_MPC830X) &&
 		    !IS_ENABLED(CONFIG_ARCH_MPC831X) &&
 		    !IS_ENABLED(CONFIG_ARCH_MPC8360) &&
-		    !IS_ENABLED(CONFIG_MPC837x)) {
+		    !IS_ENABLED(CONFIG_ARCH_MPC837X)) {
 			debug("%s: odt_rd_cfg value %d invalid.\n",
 			      ofnode_get_name(node), odt_rd_cfg);
 			return -EINVAL;
@@ -201,7 +201,7 @@
 	switch (odt_wr_cfg) {
 	case ODT_WR_ONLY_OTHER_DIMM:
 		if (!IS_ENABLED(CONFIG_ARCH_MPC8360) &&
-		    !IS_ENABLED(CONFIG_MPC837x)) {
+		    !IS_ENABLED(CONFIG_ARCH_MPC837X)) {
 			debug("%s: odt_wr_cfg value %d invalid.\n",
 			      ofnode_get_name(node), odt_wr_cfg);
 			return -EINVAL;
@@ -213,7 +213,7 @@
 		if (!IS_ENABLED(CONFIG_ARCH_MPC830X) &&
 		    !IS_ENABLED(CONFIG_ARCH_MPC831X) &&
 		    !IS_ENABLED(CONFIG_ARCH_MPC8360) &&
-		    !IS_ENABLED(CONFIG_MPC837x)) {
+		    !IS_ENABLED(CONFIG_ARCH_MPC837X)) {
 			debug("%s: odt_wr_cfg value %d invalid.\n",
 			      ofnode_get_name(node), odt_wr_cfg);
 			return -EINVAL;