machine/icd2061a: Fix out of bounds array access

[987123879113]

Just to be sure I checked and all other usages of m_reg_clocks are using constants instead of variables. truckk and ujlnow are both still booting so code-wise it's working as expected (they rely on the feature clock working properly to even boot).

cc: @happppp

[happppp]

Should it keep the clock unchanged if select = VCLKOUT_FORCED_HIGH or VCLKOUT_HIGH_Z?

[987123879113]

There's a TODO for those clock settings in the header of the file. I never found anything that used those so they're left unimplemented since I didn't want to implement it if I couldn't test it.

[987123879113]

Added in a logger for TODOs and made it print out a message if it encounters one of the unimplemented clock settings instead of silently ignoring it entirely.