linux: add ioctls and structures for n_gsm
linux: add ioctls and structures for n_gsm

n_gsm is a new line discipline that implements the 3GPP 07.10
multiplexing protocol in the kernel.

Distrotech/vala,flobrosch/vala-fixes,tjol/vala-tjol,GNOME/vala,playya/vala,GNOME/vala,frida/vala,playya/vala,frida/vala,GNOME/vala,severinh/vala,rvu95/vala,jessevdk/vala,kamanashisroy/aroop,severinh/vala,Distrotech/vala,spidermonkdust/vala,frida/vala,xdave/pvala,rvu95/vala,GNOME/vala,kamanashisroy/aroop,Distrotech/vala,frida/vala,jessevdk/vala,flobrosch/vala-fixes,jessevdk/vala,frida/vala,tjol/vala-tjol,spidermonkdust/vala,kamanashisroy/aroop,spidermonkdust/vala,tjol/vala-tjol,severinh/vala,playya/vala,rvu95/vala,flobrosch/vala-fixes