ALSA: hda: beep: Simplify keep-power-at-enable behavior

ALSA: hda: beep: Simplify keep-power-at-enable behavior

[ Upstream commit 4ac62a6fa730c4ffa6213c76269e1f8c3b4a26d2 ]

The recent fix for IDT codecs to keep the power up while the beep is
enabled can be better integrated into the beep helper code.
This patch cleans up the code with refactoring.

Fixes: 1d24d288c707 ("ALSA: hda/sigmatel: Keep power up while beep is enabled")
Link: https://lore.kernel.org/r/20220906092306.26183-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>