clk: tegra: Fix a bunch of sparse warnings

The second to last parameter of the TEGRA_CLK_PERIPH macro denotes a
table and should therefore users should pass in NULL instead of 0.

Fixes a bunch of sparse warnings like this:

	warning: Using plain integer as NULL pointer
Reviewed-by: NPaul Walmsley <paul@pwsan.com>
Signed-off-by: NThierry Reding <treding@nvidia.com>

drivers/clk/tegra/clk-tegra-periph.c

@@ -218,7 +218,7 @@
 		.clk_id = _clk_id,					\
 		.p.parent_name = _parent_name,				\
 		.periph = TEGRA_CLK_PERIPH(0, 0, 0, 0, 0, 0, 0,		\
-				_clk_num, _gate_flags, 0, NULL),	\
+				_clk_num, _gate_flags, NULL, NULL),	\
 		.flags = _flags						\
 	}