usb: phy: msm: reset controller is mandatory now

Commit a2734543 "usb: phy: msm: Use reset framework for LINK
and PHY resets" introduced a mandatory call to reset_control_get
into the msm usb phy driver, which means we have to add a Kconfig
dependency on the API to avoid this build error:

phy/phy-msm-usb.c: In function 'msm_otg_read_dt':
phy/phy-msm-usb.c:1461:2: error: implicit declaration of function 'devm_reset_control_get' [-Werror=implicit-function-declaration]
  motg->link_rst = devm_reset_control_get(&pdev->dev, "link");
  ^

Since the usb-ehci-msm driver currently selects the OTG driver,
we could still get a broken dependency here. To solve that,
this patch also removes the 'select', which turns out to be
unnecessary.

Reviewed-by: Ivan T. Ivanov <iivanov@mm-sol.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>