Overwrite default CODAL uBit.audio.levelSPL 8-bit conversion range. (#481)

codal-core has set the default min and max values to 35 and 100 in:
lancaster-university/codal-core@d376f1a

MakeCode uses 52 to 120, and MicroPython 52 to 100:
- https://github.com/microsoft/pxt-microbit/blob/v7.1.31/libs/microphone/microphone.cpp#L8-L9
- microbit-foundation/micropython-microbit-v2#132 (comment)

With the current SoundLevelSPL we don't get values much larger than
100 dB, so it makes sense to make the micro:bit target default to
100 instead of 120.

This was originally intended to go in codal-microbit-v2 v0.2.44,
but it we never got around to it.

Author: microbit-carlos

target-locked.json

@@ -32,6 +32,8 @@
         "HARDWARE_NEOPIXEL": 1,
         "LED_MATRIX_MAXIMUM_BRIGHTNESS": 245,
         "LED_MATRIX_MINIMUM_BRIGHTNESS": 1,
+        "LEVEL_DETECTOR_SPL_8BIT_000_POINT": 52.0,
+        "LEVEL_DETECTOR_SPL_8BIT_255_POINT": 100.0,
         "MBED_CONF_NORDIC_NRF_LF_CLOCK_SRC": "NRF_LF_SRC_XTAL",
         "MESSAGE_BUS_LISTENER_MAX_QUEUE_DEPTH": 10,
         "NRF52ADC_SOFTWARE_OVERSAMPLING": 1,

target.json

@@ -43,6 +43,8 @@
         "HARDWARE_NEOPIXEL": 1,
         "CODAL_TIMER_32BIT": 1,
         "DEVICE_BLE": 1,
+        "LEVEL_DETECTOR_SPL_8BIT_000_POINT": 52.0,
+        "LEVEL_DETECTOR_SPL_8BIT_255_POINT": 100.0,
         "CODAL_VERSION": "\"unknown\""
     },
     "definitions":"-DAPP_TIMER_V2 -DAPP_TIMER_V2_RTC1_ENABLED -DNRF_DFU_TRANSPORT_BLE=1 -DNRF52833_XXAA -DNRF52833 -DTARGET_MCU_NRF52833 -DNRF5 -DNRF52833 -D__CORTEX_M4 -DS113 -DTOOLCHAIN_GCC -D__START=target_start",