The clock framework has no debug output of its own, so a provider
reporting a clock it could not register, or a tree it wants to dump at
startup, has to reach for the bare _err() and _info() macros. Those are
gated only by DEBUG_ERROR and DEBUG_INFO, so the output cannot be turned
off without silencing every subsystem that has not been given its own
level.
Add CONFIG_DEBUG_CLK with the usual three levels and the matching
clkerr(), clkwarn() and clkinfo() macros, alongside the pinctrl ones in
the previous commit and for the same reason.
Nothing selects these, so the build is unchanged until a provider starts
using them.
Assisted-by: Claude:claude-opus-5
Signed-off-by: Justin Hammond <justin@dynam.ac>