support/config-fragments: remove sourcery-nios2.config

The Sourcery CodeBench Nios-II 2018.05 external toolchain will be
removed, first remove it from toolchain-configs.csv used by test-pkg
and genrandconfig scripts.

Signed-off-by: Romain Naour <romain.naour@smile.fr>

support/config-fragments/autobuild/sourcery-nios2.config

@@ -1,3 +0,0 @@
-BR2_nios2=y
-BR2_TOOLCHAIN_EXTERNAL=y
-BR2_TOOLCHAIN_EXTERNAL_CODESOURCERY_NIOSII=y

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

@@ -65,4 +65,3 @@ support/config-fragments/autobuild/linaro-aarch64-be.config,x86
 support/config-fragments/autobuild/linaro-arm.config,x86
 support/config-fragments/autobuild/sourcery-mips64.config,x86
 support/config-fragments/autobuild/sourcery-mips.config,x86
-support/config-fragments/autobuild/sourcery-nios2.config,x86