mpg123: cleanup after r19300 (don't introduce unneeded hidden configs)

package/multimedia/mpg123/Config.in

@@ -5,9 +5,3 @@ config BR2_PACKAGE_MPG123
 	  MPEG 1.0/2.0 layers 1, 2 and 3.
 
 	  http://www.mpg123.de/
-
-config BR2_PACKAGE_MPG123_ALSA
-	bool
-	default y
-	depends on BR2_PACKAGE_ALSA_LIB
-

package/multimedia/mpg123/mpg123.mk

@@ -13,7 +13,7 @@ MPG123_TARGET_BIN:=usr/bin/mpg123
 
 # Check if ALSA is built, then we should configure after alsa-lib so
 # ./configure can find alsa-lib.
-ifeq ($(BR2_PACKAGE_MPG123_ALSA),y)
+ifeq ($(BR2_PACKAGE_ALSA_LIB),y)
 MPG123_USE_ALSA:=--with-audio=alsa
 MPG123_ALSA_DEP:=alsa-lib
 endif