support LGT8F328P, a ATMega328P like MCU with 32M internal RC

[mzhboy]

LGT8F328P Arduino Clone Chip ATMega328P

It has high speed internal 32MHz RC that means no ext oscillator needed for v-usb application.

It has different flash compare to the original mega328p, the page size is 1kB and it can only write by 32bit, the relocated interrupt table base address has to be 512 byte aligned。