usb: gadget: udc: renesas_usb3: should call devm_phy_get() before add udc

usb: gadget: udc: renesas_usb3: should call devm_phy_get() before add udc

BugLink: http://bugs.launchpad.net/bugs/1790188
commit 003bc1dee216b1fb8e02040a95672bea0f1fe797 upstream.

This patch fixes an issue that this driver cannot call phy_init()
if a gadget driver is alreadly loaded because usb_add_gadget_udc()
might call renesas_usb3_start() via .udc_start.
This patch also revises the typo (s/an optional/optional/).

Fixes: 279d4bc64060 ("usb: gadget: udc: renesas_usb3: add support for generic phy")
Cc: <stable@vger.kernel.org> # v4.15+
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>