qemu/sparc-ss10: switch to v8 optimization

Switch to generic V8 optimization for gcc since we dropped the explicit
supersparc one and works just the same.

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

configs/qemu_sparc_ss10_defconfig

@@ -1,6 +1,6 @@
 # Architecture
 BR2_sparc=y
-BR2_sparc_supersparc=y
+BR2_sparc_v8=y
 
 # filesystem
 BR2_TARGET_ROOTFS_EXT2=y