Added TARGET_DISCO_F469NI in USBHOST\USBHost\TARGET_STM\USBHALHost_STM_TARGET.h

Dependents:   DISCO-F469NI_USB_Disk STM32F4xx_USB_Memory

Fork of USBHOST by ST

USBHost/USBHALHost_M451.cpp/shortlog@7ebd364a6be5: not found in manifest