score: add asm/asm-offsets.h wrapper

A recent kbuild patch moved asm-offsets.h to include/generated. Provide
a wrapper header as for other architectures.
Signed-off-by: Michal Marek <mmarek@suse.cz>

arch/score/include/asm/asm-offsets.h

+#include <generated/asm-offsets.h>