toolchain-buildroot: musl only supports 64bit variant of risc-v

Reported-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

toolchain/toolchain-buildroot/Config.in

@@ -84,7 +84,7 @@ config BR2_TOOLCHAIN_BUILDROOT_MUSL
 	depends on BR2_aarch64	   || BR2_arm   || BR2_armeb   || BR2_i386 || \
 		   BR2_microblaze  || BR2_mips  || BR2_mipsel  || BR2_mips64 || \
 		   BR2_mips64el    || BR2_or1k  || BR2_powerpc || BR2_powerpc64 || \
-		   BR2_powerpc64le || BR2_riscv || BR2_sh      || BR2_x86_64
+		   BR2_powerpc64le || BR2_RISCV_64 || BR2_sh   || BR2_x86_64
 	depends on !BR2_powerpc_SPE # not supported, build breaks
 	# sh2 nommu is supported by musl, but we don't have support
 	# for it in Buildroot.