goarch.bbclass: do not leak TUNE_FEATURES into crosssdk task signatures

The default assignments look like this:
TARGET_GO386 = "${@go_map_386(d.getVar('TARGET_ARCH'), d.getVar('TUNE_FEATURES'), d)}"

TUNE_FEATURES is a target-specific variable, and so should be used
only for target builds. The change is similar to what is already done
for native packages.

(From OE-Core rev: cfff8e968257c44880caa3605e158764ed5c6a2a)

Signed-off-by: Alexander Kanavin <alex@linutronix.de>
Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes-recipe/goarch.bbclass

@@ -24,6 +24,9 @@ TARGET_GOMIPS = "${@go_map_mips(d.getVar('TARGET_ARCH'), d.getVar('TUNE_FEATURES
 TARGET_GOARM:class-native = "7"
 TARGET_GO386:class-native = "sse2"
 TARGET_GOMIPS:class-native = "hardfloat"
+TARGET_GOARM:class-crosssdk = "7"
+TARGET_GO386:class-crosssdk = "sse2"
+TARGET_GOMIPS:class-crosssdk = "hardfloat"
 TARGET_GOTUPLE = "${TARGET_GOOS}_${TARGET_GOARCH}"
 GO_BUILD_BINDIR = "${@['bin/${HOST_GOTUPLE}','bin'][d.getVar('BUILD_GOTUPLE') == d.getVar('HOST_GOTUPLE')]}"