go-crosssdk: avoid host contamination by GOCACHE

By default GOCACHE is set to $HOME/.cache.

Same issue for all other go recipes had been fixed by commit 9a6d208b:
[ go: avoid host contamination by GOCACHE ]

but that commit missed go-crosssdk recipe.

Signed-off-by: Robert Andersson <robert.m.andersson@atlascopco.com>
Signed-off-by: Ming Liu <liu.ming50@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>