ASoC: qdsp6: fix compile-testing without CONFIG_OF

ASoC: qdsp6: fix compile-testing without CONFIG_OF

The driver builds cleanly only when CONFIG_OF is enabled, otherwise the
compiler notices an unused symbol:

sound/soc/qcom/qdsp6/q6usb.c:401:34: error: 'q6usb_dai_device_id' defined but not used [-Werror=unused-const-variable=]

The driver does not support legacy board files, so the of_match_ptr()
annotation has no use here and can be removed to avoid the warning.

Fixes: e0dd9240f13a ("ASoC: qcom: qdsp6: Fetch USB offload mapped card and PCM device")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20250523121152.2292574-1-arnd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>