Only use gold linker on arm/arm64

gold linker seems to be abandoned upstream, and is only required for arm
due to a bug in old bfd linker. But there are no gold linker for
riscv64, so only pull in gold on arm/arm64.

fixes: k0sproject#4665
ref: golang/go#22040
Signed-off-by: Natanael Copa <ncopa@mirantis.com>

build/Dockerfile

@@ -1,6 +1,11 @@
 ARG BUILDIMAGE
 FROM $BUILDIMAGE
-RUN apk add --no-cache make gcc musl-dev binutils-gold
+RUN \
+  case "$(uname -m)" in \
+  arm*|aarch64) pkg="binutils-gold";; \
+  *) pkg="binutils";; \
+  esac; \
+  apk add --no-cache make gcc musl-dev $pkg
 
 ENV \
   HOME="/run/k0s-build" \