clk: imx: clk-pllv3: Switch to clk_hw based API

Switch the imx_clk_hw_pllv3 function to clk_hw based API, rename
accordingly and add a macro for clk based legacy. This allows us
to move closer to a clear split between consumer and provider clk
APIs.

Signed-off-by: Abel Vesa <abel.vesa@nxp.com>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>