ALSA: compress_offload: Add SNDRV_COMPRESS_TSTAMP64 ioctl

The previous patch introduced the internal infrastructure for handling
64-bit timestamps. This patch exposes this capability to user-space.

Define the new ioctl command SNDRV_COMPRESS_TSTAMP64, which allows
applications to fetch the overflow-safe struct snd_compr_tstamp64.

The ioctl dispatch table is updated to handle the new command by
calling a new snd_compr_tstamp64 handler, while the legacy path is
renamed to snd_compr_tstamp32 for clarity.

This patch bumps the SNDRV_COMPRESS_VERSION to 0.4.0.

Reviewed-by: Miller Liang <millerliang@google.com>
Tested-by: Joris Verhaegen <verhaegen@google.com>
Signed-off-by: Joris Verhaegen <verhaegen@google.com>
Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20250905091301.2711705-3-verhaegen@google.com