unmark the sparc targets as broken, they build if you disable shared libgcc

target/Config.in.arch

@@ -39,10 +39,8 @@ config BR2_sh64
 	bool "superh64"
 config BR2_sparc
 	bool "sparc"
-	depends on BROKEN # uclibc linker errors
 config BR2_sparc64
 	bool "sparc64"
-	depends on BROKEN # uclibc libm linker errors
 config BR2_x86_64
 	bool "x86_64"
 endchoice