libnm,core: fix device TYPE for Wi-Fi P2P devices

Don't use "wifip2p" for the type description.

    $ nmcli device
    DEVICE             TYPE      STATE         CONNECTION
    wlan0              wifi      connected     x
    p2p-dev-wlan0      wifip2p   disconnected  --
4 jobs for th/wifi-p2p-type-description in 36 minutes and 57 seconds (queued for 1 second)
Status Job ID Name Coverage
  Test
passed #136420
build_f28

00:36:56

passed #136421
build_f_latest

00:36:21

passed #136422
allowed to fail
build_f_rawhide

00:25:46

passed #136419
allowed to fail
checkpatch

00:06:20