Raytac: target removal

No files to build - should not be in targets
Reverts part of the #6178

Author: 0xc0170

targets/targets.json

@@ -3617,13 +3617,6 @@
         "macros_add": ["TARGET_MCU_NORDIC_16K", "TARGET_MCU_NRF51_16K_S130", "TARGET_MCU_NRF51_16K"],
         "public": false
     },
-    "Raytac_MDBT40": {
-        "inherits": ["MCU_NRF51_16K_UNIFIED_S130"],
-        "macros_add": ["TARGET_NRF_LFCLK_RC"],
-        "release_versions": ["2"],
-        "device_has": ["ANALOGIN", "I2C", "I2C_ASYNCH", "INTERRUPTIN", "LOWPOWERTIMER", "PORTIN", "PORTINOUT", "PORTOUT", "PWMOUT", "RTC", "SERIAL", "SERIAL_ASYNCH", "SERIAL_FC", "SLEEP", "SPI", "SPI_ASYNCH", "SPISLAVE"],
-        "device_name": "nRF51822_xxAA"
-    },
     "MCU_NRF51_32K_UNIFIED": {
         "inherits": ["MCU_NRF51_UNIFIED"],
         "extra_labels_add": ["MCU_NORDIC_32K", "MCU_NRF51_32K"],