ARM: davinci: DA850: move da850_register_pm to .init.text

All callers (board-mityomapl138.c and board-da850-evm.c) use it in
__init functions only.

This fixes:

	WARNING: vmlinux.o(.text+0xd664): Section mismatch in reference from the function da850_register_pm() to the function .init.text:da8xx_get_mem_ctlr()
	The function da850_register_pm() references
	the function __init da8xx_get_mem_ctlr().
	This is often because da850_register_pm lacks a __init
	annotation or the annotation of da8xx_get_mem_ctlr is wrong.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>

arch/arm/mach-davinci/da850.c

@@ -1026,7 +1026,7 @@ static int da850_round_armrate(struct clk *clk, unsigned long rate)
 }
 #endif
 
-int da850_register_pm(struct platform_device *pdev)
+int __init da850_register_pm(struct platform_device *pdev)
 {
 	int ret;
 	struct davinci_pm_config *pdata = pdev->dev.platform_data;