move the baseline arch to z13 for s390x in F-38+

https://fedoraproject.org/wiki/Changes/z13BaselineForIBMZ

waiting for FESCo approval

diff for the generated configs

diff --git a/kernel-s390x-fedora.config b/kernel-s390x-fedora.config
index 34499aeae..96dd1f05b 100644
--- a/kernel-s390x-fedora.config
+++ b/kernel-s390x-fedora.config
@@ -3115,7 +3115,7 @@ CONFIG_MAGIC_SYSRQ=y
 # CONFIG_MANAGER_SBS is not set
 CONFIG_MANTIS_CORE=m
 # CONFIG_MARCH_Z10 is not set
-# CONFIG_MARCH_Z13 is not set
+CONFIG_MARCH_Z13=y
 # CONFIG_MARCH_Z14 is not set
 # CONFIG_MARCH_Z15 is not set
 # CONFIG_MARCH_Z16 is not set
@@ -3123,7 +3123,7 @@ CONFIG_MANTIS_CORE=m
 # CONFIG_MARCH_Z900 is not set
 # CONFIG_MARCH_Z9_109 is not set
 # CONFIG_MARCH_Z990 is not set
-CONFIG_MARCH_ZEC12=y
+# CONFIG_MARCH_ZEC12 is not set
 CONFIG_MARVELL_10G_PHY=m
 CONFIG_MARVELL_88X2222_PHY=m
 # CONFIG_MARVELL_CN10K_TAD_PMU is not set