libopalevent.h: remove unused enum
libopalevent.h: remove unused enum

Signed-off-by: Stewart Smith <ec31ab75ddf977353c8f660f92ea8b23f64aef25@linux.vnet.ibm.com>
Reviewed-by: Vasant Hegde <a6d753843573f7bfed5075c1e875b0be8007a0ab@linux.vnet.ibm.com>

leitao/ppc64-diag,leitao/ppc64-diag,leitao/ppc64-diag,leitao/ppc64-diag