Strange. haven't heared about that. But if it's neither on lspci nor on lsusb, I'm really surprise, how the non-pc's should use this card?!
It might be a special "resevered"-minipcie-pin which must be put on 3.3V. Or the card doesn't like the additional I2C, which is used by the ME to connect to the Wifi card.
I have found this datasheet http://www.compex.com.sg/wp-content/uploads/2015/09/WLE900VX-Hw-Guide-v1.1.p... for the card. There are 4 pins (8, 10, 12, 14) which have a different function as the one I found here http://pinoutguide.com/Slots/mini_pcie_pinout.shtml
Specifically, these are MCI_CLK_IN, MCI_CLK_OUT, MCI_DATA_OUT, MCI_DATA_IN (on the pinout webpage there is instead VCC, I/O, CLK, RST).
I do not think this is the problem though, since ports 8, 10, 12 and 14 are marked as reserved...
Can you write a mail to compex about it? IMHO you should see the card on lspci anyhow, even if it's missing some magic init procedures.
As I have written, the Lenovo 3000 N200 does see the card. I have written to Compex, I will see what I'll found out.
Still I think it should be worthwhile to try to adapt the coreboot code for Intel wifi cards for this card also.
M