fw/board: use stereo mic capture in all recovery builds

Commit 6ae8c1e ("fw/board: use stereo mic capture in MFG builds")
restored stereo PDM capture for the mic test, but only gated it on
CONFIG_MFG. The mic test apps live in the recovery firmware and are
built for every PRF variant, so a non-MFG PRF still captured mono and
hit the same 2x-speed playback and missing second microphone.

Gate stereo capture on CONFIG_RECOVERY_FW instead, which MFG builds
also define.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Signed-off-by: Gerard Marull-Paretas <gerard@teslabs.com>

Author: gmarull

src/fw/board/boards/board_getafix.c

@@ -524,8 +524,8 @@ static const MicDevice mic_device = {
     .pdm_dma_irq = DMAC1_CH5_IRQn,
     .pdm_irq = PDM1_IRQn,
     .pdm_irq_priority = 5,
-#ifdef CONFIG_MFG
-    // MFG mic test needs stereo capture to verify both microphones
+#ifdef CONFIG_RECOVERY_FW
+    // PRF mic test needs stereo capture to verify both microphones
     .channels = 2,
 #else
     .channels = 1,

src/fw/board/boards/board_obelix.c

@@ -606,8 +606,8 @@ static const MicDevice mic_device = {
     .pdm_dma_irq = DMAC1_CH5_IRQn,
     .pdm_irq = PDM1_IRQn,
     .pdm_irq_priority = 5,
-#ifdef CONFIG_MFG
-    // MFG mic test needs stereo capture to verify both microphones
+#ifdef CONFIG_RECOVERY_FW
+    // PRF mic test needs stereo capture to verify both microphones
     .channels = 2,
 #else
     .channels = 1,