drivers/pinctrl, drivers/clk: Add debug output levels.

[Fishwaldo]

Summary

Neither the pinctrl nor the clock framework has debug output of its own, so a
provider reporting a pad it could not configure, or a clock it could not
register, has to reach for the bare _err() and _info() macros. Those are
gated only by DEBUG_ERROR and DEBUG_INFO, so their output cannot be turned
off without silencing every subsystem that has not been given its own level.

This adds CONFIG_DEBUG_PINCTRL and CONFIG_DEBUG_CLK, each with the usual
three levels, and the matching pinctrlerr()/pinctrlwarn()/pinctrlinfo()
and clkerr()/clkwarn()/clkinfo() macros. Both follow the shape of the
DEBUG_RESET block they sit beside, and both are placed next to it in
Kconfig and in include/nuttx/debug.h.

One commit each, so either can be taken on its own.

Impact

None until something uses them. Nothing selects the new symbols, they default
to n, and each depends on its subsystem being enabled, so the build is
unchanged for every existing configuration. Additions only: no existing line is
modified.

Testing

sim:nsh configured with CLK, PINCTRL, DEBUG_CLK, DEBUG_PINCTRL and
both _INFO levels enabled: kconfig parses, all six symbols appear in the
resulting .config, and the image builds.

CONFIG_DEBUG_PINCTRL=y
CONFIG_DEBUG_PINCTRL_INFO=y
CONFIG_DEBUG_CLK=y
CONFIG_DEBUG_CLK_INFO=y

Also built with the symbols left at their defaults, which is a no-op change.

[github-actions]

MemBrowse Memory Report

hifive1-revb

• flash: .text -4 B (-0.0%, 83,376 B / 4,194,304 B, total: 2% used)
  No memory changes detected for:
• arduino-mega2560
• esp32-devkitc
• mirtoo
• qemu-armv8a
• qemu-intel64
• rx65n-rsk2mb
• s698pm-dkit
• stm32-nucleo-f103rb

[Fishwaldo]

(FYI, Another PR coming soon that utilizes these logging functions)