ASoC: mid-x86 - remove the flag in makefile

previous commit e62255f2 introduced DDEBUG flag in Makefile
This causes all debug statemenets to be ON.

This patch removes this flag

Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Harsha Priya <priya.harsha@intel.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>