go-runtime: remove conflict files from -dev packages

go-runtime: remove conflict files from -dev packages

fix below error:
file /usr/lib64/go/src/cmd/cgo/zdefaultcc.go conflicts between attempted installs of go-dev-1.12.6-r0.core2_64 and go-runtime-dev-1.12.6-r0.core2_64
file /usr/lib64/go/src/cmd/go/internal/cfg/zdefaultcc.go conflicts between attempted installs of go-dev-1.12.6-r0.core2_64 and go-runtime-dev-1.12.6-r0.core2_64

these 2 files existed in both go-dev and go-runtime-dev
remove it from go-runtime-dev to fix the problem

(From OE-Core rev: 60dcae509a210f2cae8eda525a1b006663aef9bf)

Signed-off-by: Changqing Li <changqing.li@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>