raspberrypi: Enable mp3 playback

The rp2040 is _very_ marginal for mp3 playback, and currently sometimes triggers a bug that gives garbled audio output.  However, it does work for some limited situations.

Author: jepler

ports/raspberrypi/mpconfigport.mk

@@ -25,6 +25,7 @@ endif
 
 CIRCUITPY_FRAMEBUFFERIO = 1
 CIRCUITPY_FULL_BUILD = 1
+CIRCUITPY_AUDIOMP3 ?= 1
 CIRCUITPY_BITOPS = 1
 CIRCUITPY_PWMIO = 1
 CIRCUITPY_RGBMATRIX = 1
@@ -47,7 +48,6 @@ CIRCUITPY_AUDIOPWMIO ?= 1
 
 # These libraries require Cortex M4+ for fancy math instructions.
 CIRCUITPY_AUDIOMIXER ?= 0
-CIRCUITPY_AUDIOMP3 ?= 0
 
 INTERNAL_LIBM = 1