Novena headers to linux GPIO mappings

For reference, mapping of "extra" pins on Novena internal serial headers to GPIO pin numbers.

The layout is like this:

 |--------------
 |
 | d  u
 | e  a
 | b  r
 | u  t
 | g  4  <- pin 1/GND
 |
 | u
 | a
 | r
 | t
 | 3     <- pin 1/GND
 | 

row closer to edge	row closer to buttons
NC	UART4_RTS - CSI0_DAT16 - GPIO6_IO2 - linux162
UART2_TXD - console	UART4_TXD - senoko
UART2_RXD - console	UART4_RXD - senoko
NC	3.3V (via diode)
NC	UART4_CTS - CSI0_DAT17 - GPIO6_IO3 - linux163
GND	GND
GPT_CAPIN1 - SD1_DAT0 - GPIO1_IO16 - linux16
UART3_TXD - EIM_D24 - GPIO3_IO24 - linux88
UART3_RXD - EIM_D25 - GPIO3_IO25 - linux89
3.3V (via diode)
GPT_CLKIN - SD1_CLK - GPIO1_IO20 - linux20
GND