sm8350-common: Drop unnecessary audio HAL flags from BoardConfig

BOARD_USES_ALSA_AUDIO is only used to determine wether the audio HAL
is built from source, but we ship the prebuilt stock HAL.
AUDIO_FEATURE_ENABLED_GEF_SUPPORT is used to modify the source-built
audio HAL, which does not have an effect for us.

Change-Id: I652de533d1c21a0e45dc7406bd0698326c5dbcd7

BoardConfigCommon.mk

@@ -42,13 +42,10 @@ TARGET_2ND_CPU_VARIANT_RUNTIME := kryo385
 AUDIO_FEATURE_ENABLED_EXTN_FORMATS := true
 AUDIO_FEATURE_ENABLED_HDMI_SPK := true
 AUDIO_FEATURE_ENABLED_PROXY_DEVICE := true
-#AUDIO_FEATURE_ENABLED_AHAL_EXT := true
 
 AUDIO_FEATURE_ENABLED_EXTENDED_COMPRESS_FORMAT := true
-AUDIO_FEATURE_ENABLED_GEF_SUPPORT := true
 AUDIO_FEATURE_ENABLED_GKI := true
 BOARD_SUPPORTS_SOUND_TRIGGER := true
-BOARD_USES_ALSA_AUDIO := true
 
 # Audio policy
 USE_CUSTOM_AUDIO_POLICY := 1