ARM: OMAP: hwmod: fix an incorrect clk type cast with _get_clkdm

If the main clock for a hwmod is of basic clock type, it is illegal to type
cast this to clk_hw_omap and will result in bogus data. Fixed by checking
the clock flags before attempting the type cast.
Signed-off-by: Tero Kristo <t-kristo@ti.com>
Tested-by: Nishanth Menon <nm@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

arch/arm/mach-omap2/omap_hwmod.c

@@ -686,6 +686,8 @@ static struct clockdomain *_get_clkdm(struct omap_hwmod *oh)
 	if (oh->clkdm) {
 		return oh->clkdm;
 	} else if (oh->_clk) {
+		if (__clk_get_flags(oh->_clk) & CLK_IS_BASIC)
+			return NULL;
 		clk = to_clk_hw_omap(__clk_get_hw(oh->_clk));
 		return  clk->clkdm;
 	}