OLIMEXINO - Initial support for the OLIMEXINO board.

PWM and ADC configuration is the same as the naze32 for now.  Requires an accelerometer is connected via I2C2.

I2C signals SDA2 and SCL2 are on the UEXT header (Pins 6 and 5 respectively)
USART signals TX and RX are on the CON3/CON4 headers (TX = D7, RX = D8)

Onboard LEDs (LED1/LED2) working.
Buzzer support removed for now as it conflicted with PWM map and LEDs.
mma845x support disabled as it conflicted with an LED.
Relocated some NAZE specific comments.

Disabling PWM2 as an input as it conflicts with the yellow onboard LED2.