net: phy: fix phy_get_internal_delay accessing an empty array

In the Linux kernel, the following vulnerability has been resolved: net: phy: fix phy_get_internal_delay accessing an empty array The phy_get_internal_delay function could try to access to an empty array in the case that the driver is calling phy_get_internal_delay without defining delay_values and rx-internal-delay-ps or tx-internal-delay-ps is defined to 0 in the device-tree. This will lead to "unable to handle kernel NULL pointer dereference at virtual address 0". To avoid this kernel oops, the test should be delay >= 0. As there is already delay < 0 test just before, the test could only be size == 0.