Removed all references to a specific MCU in "generic" files
Inclusion of generic <msp430.h> file is done in cpu.h
Made the headers of files in 'cpu/msp430x16x' and 'cpu/cc430' generic
Added definition of correct MCU model in MSP430-based board headers
Removed 'flashrom.c' from the 'msp430-common' directory
since flash management differs with the MSP430 family