Fix Mynewt build for Microchip PIC32MZ devices.
definition of DEBUG breaks Microchip pic32 builds for Mynewt.
When MCU is not VALENTYUSB_EPTRI there is no need to have any
preprocessor definitions.
It may not look like a big deal but for xc32 builds, compiler
automatically force-includes some file that have structure with field name
DEBUG that result in build error in dcd_eptri.c when this file
is not really needed.
Moving DEBUG and LOG_USB few lines down should not break eptri builds.
Jerzy Kasenberg