[edn/rtl] field enable has just two valid values
[edn/rtl] field enable has just two valid values

For any field enable, only 0xa and 0x5 take action.

Signed-off-by: Mark Branstad <d7ca710cc6ec5dc810c866dae5369b19445fbeef@wdc.com>

lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan