usb: dwc3-meson-g12a: fix usb2 PHY glue init when phy0 is disabled

In the Linux kernel, the following vulnerability has been resolved:

usb: dwc3-meson-g12a: fix usb2 PHY glue init when phy0 is disabled

When only PHY1 is used (for example on Odroid-HC4), the regmap init code

uses the usb2 ports when doesn't initialize the PHY1 regmap entry.

This fixes:

Unable to handle kernel NULL pointer dereference at virtual address 0000000000000020

...

pc : regmap_update_bits_base+0x40/0xa0

lr : dwc3_meson_g12a_usb2_init_phy+0x4c/0xf8

...

Call trace:

regmap_update_bits_base+0x40/0xa0

dwc3_meson_g12a_usb2_init_phy+0x4c/0xf8

dwc3_meson_g12a_usb2_init+0x7c/0xc8

dwc3_meson_g12a_usb_init+0x28/0x48

dwc3_meson_g12a_probe+0x298/0x540

platform_probe+0x70/0xe0

really_probe+0xf0/0x4d8

driver_probe_device+0xfc/0x168

...