RFR(T): 8214451: PPC64/s390: Clean up unused CRC32 prototype and function

[Gustavo Romero]

Hi,

Could the following change be reviewed please?

It removes a prototype, generate_load_table_addr() (on PPC64), and an unused
function, kernel_crc32_2word() (on PPC64 and s390), in the CRC32 code.

Bug   : https://bugs.openjdk.java.net/browse/JDK-8214451
Webrev: http://cr.openjdk.java.net/~gromero/8214451/v1/

Thank you and best regards,
Gustavo