VRBRAIN: added startup of internal mag's driver for VR Brain Standard 5
AP_relay: added default relay pin for VRBRAIN
AP_HAL_VRBRAIN: added management for external relay 1 and 2
AP_HAL_VRBRAIN: enable 2nd GPS for VRBRAIN 5
AP_HAL: VRBRAIN corrected EEPROM size and added terrain folder on MicroSD