clk: mediatek: mark mtk_infrasys_init_early __init

On gcc-4.6, we get a harmless link-time warning:

WARNING: vmlinux.o(.text.unlikely+0x196a0): Section mismatch in reference from the function mtk_infrasys_init_early() to the function .init.text:mtk_clk_register_cpumuxes()
The function mtk_infrasys_init_early() references
the function __init mtk_clk_register_cpumuxes().
This is often because mtk_infrasys_init_early lacks a __init
annotation or the annotation of mtk_clk_register_cpumuxes is wrong.

Newer compilers inline this function so they don't warn, but
marking it __init is the right solution for all versions.

Fixes: e9862118 ("clk: mediatek: Add MT2701 clock support")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

drivers/clk/mediatek/clk-mt2701.c

@@ -750,7 +750,7 @@ static const struct mtk_fixed_factor infra_fixed_divs[] = {
 
 static struct clk_onecell_data *infra_clk_data;
 
-static void mtk_infrasys_init_early(struct device_node *node)
+static void __init mtk_infrasys_init_early(struct device_node *node)
 {
 	int r, i;