RFR 8046046: Test sun/security/pkcs11/Signature/TestDSAKeyLength.java fails intermittently on Solaris 11 in 8u40 nightly

[Valerie Peng]

Tony,

Can you please help reviewing this trivial fix?
Changes are about overriding the SHA1withDSA signature upper limit to 
1024 when larger DSA key size is supported.

Webrev: http://cr.openjdk.java.net/~valeriep/8046046/webrev.00/

Thanks,
Valerie