If we have USB gadgets disabled and USB_MUSB_HOST set, we get
errors "possible irq lock inverssion dependency detected"
errors during boot.

Let's fix the issue by adding start_musb flag and start
the controller after we're out of the spinlock protected
section.
Reported-by: NLadislav Michl <ladis@linux-mips.org>
Tested-by: NLadislav Michl <ladis@linux-mips.org>
Signed-off-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NBin Liu <b-liu@ti.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>