support/config-fragments: add a bootlin s390x toolchain

I do constantly get mails that fluent-bit fails to build for s390x.
So added this to ensure that the s390x architecture is checked as well
if I manually do:

$ ./utils/test-pkg -p fluent-bit -a

Signed-off-by: Thomas Devoogdt <thomas.devoogdt@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

support/config-fragments/autobuild/bootlin-s390x-z13-glibc.config

@@ -0,0 +1,5 @@
+BR2_s390x=y
+BR2_s390x_z13=y
+BR2_TOOLCHAIN_EXTERNAL=y
+BR2_TOOLCHAIN_EXTERNAL_BOOTLIN=y
+BR2_TOOLCHAIN_EXTERNAL_BOOTLIN_S390X_Z13_GLIBC_BLEEDING_EDGE=y

support/config-fragments/autobuild/toolchain-configs.csv

@@ -38,6 +38,7 @@ support/config-fragments/autobuild/bootlin-powerpc-e500mc-uclibc.config,x86_64
 support/config-fragments/autobuild/bootlin-riscv32-glibc.config,x86_64
 support/config-fragments/autobuild/bootlin-riscv64-glibc.config,x86_64
 support/config-fragments/autobuild/bootlin-riscv64-musl.config,x86_64
+support/config-fragments/autobuild/bootlin-s390x-z13-glibc.config,x86_64
 support/config-fragments/autobuild/bootlin-sh4-uclibc.config,x86_64
 support/config-fragments/autobuild/bootlin-sparc-uclibc.config,x86_64
 support/config-fragments/autobuild/bootlin-sparc64-glibc.config,x86_64