support/config-fragments/autobuild: use Bootlin toolchain for RISC-V 64 musl

Instead of using an external toolchain built specifically for the
autobuilders to test RISC-V 64/musl, use a pre-built Bootlin
toolchain.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>

support/config-fragments/autobuild/bootlin-riscv64-musl.config

@@ -0,0 +1,4 @@
+BR2_riscv=y
+BR2_RISCV_ABI_LP64=y
+BR2_TOOLCHAIN_EXTERNAL=y
+BR2_TOOLCHAIN_EXTERNAL_BOOTLIN_RISCV64_MUSL_BLEEDING_EDGE=y

support/config-fragments/autobuild/br-riscv64-musl.config

@@ -1,9 +0,0 @@
-BR2_riscv=y
-BR2_TOOLCHAIN_EXTERNAL=y
-BR2_TOOLCHAIN_EXTERNAL_CUSTOM=y
-BR2_TOOLCHAIN_EXTERNAL_DOWNLOAD=y
-BR2_TOOLCHAIN_EXTERNAL_URL="http://autobuild.buildroot.net/toolchains/tarballs/br-riscv64-musl-2020.02.tar.bz2"
-BR2_TOOLCHAIN_EXTERNAL_GCC_9=y
-BR2_TOOLCHAIN_EXTERNAL_HEADERS_4_19=y
-BR2_TOOLCHAIN_EXTERNAL_CUSTOM_MUSL=y
-BR2_TOOLCHAIN_EXTERNAL_CXX=y

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

@@ -38,6 +38,7 @@ support/config-fragments/autobuild/bootlin-powerpc64le-power8-glibc.config,x86_6
 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-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
@@ -60,7 +61,6 @@ support/config-fragments/autobuild/br-powerpc-603e-basic-cpp.config,x86_64
 support/config-fragments/autobuild/br-powerpc64-power7-glibc.config,x86_64
 support/config-fragments/autobuild/br-powerpc-internal-full.config,any
 support/config-fragments/autobuild/br-riscv64-full-internal.config,any
-support/config-fragments/autobuild/br-riscv64-musl.config,x86_64
 support/config-fragments/autobuild/br-s390x-z13-internal-glibc.config,any
 support/config-fragments/autobuild/br-xtensa-full-internal.config,any
 support/config-fragments/autobuild/linaro-aarch64.config,x86