clk: samsung: exynos5420: Avoid __clk_lookup() calls when enabling clocks

clk: samsung: exynos5420: Avoid __clk_lookup() calls when enabling clocks

This patch adds a clk ID to the mout_sw_aclk_g3d clk definition so related
clk pointer gets cached in the driver's private data and can be used
later instead of a __clk_lookup() call.

With that we have all clocks used in the clk_prepare_enable() calls in the
clk provider init callback cached in clk_data.hws[] and we can reference
the clk pointers directly rather than using __clk_lookup() with global names.

Link: https://lore.kernel.org/r/20200811151251.31613-2-s.nawrocki@samsung.com
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>