userspace-ll: re-enable the DP scheduler

The DP scheduler can now be user with userspace LL.

Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>

Author: lyakh

app/overlays/ptl/ll_userspace_overlay.conf

@@ -31,4 +31,3 @@ CONFIG_SOF_BOOT_TEST_ALLOWED=n
 CONFIG_CROSS_CORE_STREAM=n
 CONFIG_INTEL_ADSP_MIC_PRIVACY=n
 CONFIG_XRUN_NOTIFICATIONS_ENABLE=n
-CONFIG_ZEPHYR_DP_SCHEDULER=n