Generalizes PLL1 setup to take arguments, moves can-uart example usage to HAL...
Generalizes setup_clk to take arguments and renames it to setup_pll1, moves can-uart example usage to HAL and rewrites uart_pll to use setup_pll1
Generalizes setup_clk to take arguments and renames it to setup_pll1, moves can-uart example usage to HAL and rewrites uart_pll to use setup_pll1