clk: imx: Fix the build break when clk-imx8ulp build as module

Export the necessary symbols to fix the build break when clk-imx8ulp
build as module

Fixes: c43a801a ("clk: imx: Add clock driver for imx8ulp")
Signed-off-by: Jacky Bai <ping.bai@nxp.com>
Reviewed-by: Abel Vesa <abel.vesa@nxp.com>
Link: https://lore.kernel.org/r/20210917061629.3798360-1-ping.bai@nxp.comSigned-off-by: Abel Vesa <abel.vesa@nxp.com>

drivers/clk/imx/clk-composite-7ulp.c

@@ -166,3 +166,4 @@ struct clk_hw *imx8ulp_clk_hw_composite(const char *name, const char * const *pa
 	return imx_ulp_clk_hw_composite(name, parent_names, num_parents, mux_present, rate_present,
 					gate_present, reg, has_swrst);
 }
+EXPORT_SYMBOL_GPL(imx8ulp_clk_hw_composite);

drivers/clk/imx/clk-pfdv2.c

@@ -239,3 +239,4 @@ struct clk_hw *imx_clk_hw_pfdv2(enum imx_pfdv2_type type, const char *name,
 
 	return hw;
 }
+EXPORT_SYMBOL_GPL(imx_clk_hw_pfdv2);

drivers/clk/imx/clk-pllv4.c

@@ -254,3 +254,4 @@ struct clk_hw *imx_clk_hw_pllv4(enum imx_pllv4_type type, const char *name,
 
 	return hw;
 }
+EXPORT_SYMBOL_GPL(imx_clk_hw_pllv4);