usb: musb: core: print new line in the driver banner again

commit 2ac788f705e5118dd45204e7a5bc8d5bb6873835 upstream.

Commit 5c8a86e10a7c164f44537fabdc169fd8b4e7a440 (usb: musb: drop unneeded
musb_debug trickery) erroneously removed '\n' from the driver's banner.
Concatenate all the banner substrings while adding it back...

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>