usb: musb: da8xx: Fix build breakage due to typo

Commit 032ec49f (usb: musb: drop useless
board_mode usage) introduced a typo that breaks the build.

Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy@gmail.com>

[ Fixed commit message ]

Cc: Mikhail Kshevetskiy <mikhail.kshevetskiy@gmail.com>
Cc: Sergei Shtylyov <sshtylyov@mvista.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: stable@vger.kernel.org
Signed-off-by: Michael Riesch <michael.riesch@omicron.at>
Signed-off-by: Felipe Balbi <balbi@ti.com>