lib/phy: read registers before calculating pll clock

get_pll_clock always returned 0.0 on devices running the xe driver.
Initializing the register state by calling read_register before
calculating the clock fixes this.

Author: Sebastian Jaeckel

lib/phy.cpp

@@ -345,5 +345,6 @@ int phys::set_pll_clock(double current_pll_clock, double target_pll_clock, doubl
  */
 double phys::get_pll_clock(void)
 {
+	read_registers();
 	return calculate_pll_clock();
 }