USB: musb: dsps: drop duplicate phy initialisation

Since commit 39cee200 ("usb: musb: core: call init and shutdown for
the usb phy") the musb USB phy is initialised by musb_core, but the
original initialisation in the dsps-glue init callback was left in
place resulting in two calls to phy init during probe (and similarly,
two shutdowns on remove).

Drop the duplicate phy init and shutdown calls from the dsps glue in
favour of the ones in musb core, which other glue drivers rely on.

Note however that any generic phy is still initialised in the glue init
callback (just as for the other drivers).

Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Johan Hovold <johan@kernel.org>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>