phy: samsung-usb2: Remove NULL terminating entry from phys array

Current code uses num_phys settings to tell the number of entries in phys.
Thus remove the NULL terminating entry from phys array which is not necessary.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>