There are two generated files: crypto/rsakey-asn1.c and crypto/raskey-asn1.h,
after the cfc2bb32b31371d6bffc6bf2da3548f20ad48c83 commit. Let's add
.gitignore to ignore *-asn1.[ch] files.

Signed-off-by: Alexander Kuleshov
Signed-off-by: Herbert Xu