kern/59630: fdtbus_todr_attach() should be rationalized with todr_attach()

[thorpej%me.com@localhost]

>Number:         59630
>Category:       kern
>Synopsis:       fdtbus_todr_attach() should be rationalized with todr_attach()
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Sep 02 23:20:00 +0000 2025
>Originator:     Jason Thorpe
>Release:        NetBSD-current as of 20250902
>Organization:
CISCy Business
>Environment:
Generic problem.
>Description:
fdtbus_todr_attach() is a wrapper around todr_attach(), to ensure that the correct (i.e. as specified in the device tree) RTC device is attach as the system RTC.  Unfortunately, the way this interface is currently structured, drivers that wish to participate need to explicitly choose one or the other function call to register as the system RTC.

This should be handled in a more rational way that doesn't require drivers to explicitly opt-in.
>How-To-Repeat:
Code inspection.
>Fix:
Not (yet) provided.