Using misc/libtremor/tremor rather than misc/tremor, plus added the include in the android.mk of SDL_mixer
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := SDL_mixer
LOCAL_C_INCLUDES := \
$(LOCAL_PATH)/../../../../../misc/libtremor \
$(LOCAL_PATH)/.. \
$(LOCAL_PATH)/../SDL/include \
$(LOCAL_PATH)/../mikmod/include \
LOCAL_CFLAGS := -DWAV_MUSIC -DOGG_MUSIC -DOGG_USE_TREMOR -DMOD_MUSIC
LOCAL_SRC_FILES := $(notdir $(filter-out %/playmus.c %/playwave.c, $(wildcard $(LOCAL_PATH)/*.c)))
LOCAL_SHARED_LIBRARIES := SDL mikmod
LOCAL_STATIC_LIBRARIES := tremor
include $(BUILD_SHARED_LIBRARY)