sparc: remove SA_STATIC_ALLOC macro definition

This macro is not exposed to uapi and is unreferenced in the
kernel. The last reference to it was removed in commit 4c6773c3


("sparc32,leon: add support for extended interrupt controller"),
so remove the definition.

Signed-off-by: Peter Collingbourne <pcc@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>