OMAP2: Fix dss_54m_fck enable_bit

Fix an incorrect enable_bit for the OMAP2 clock dss_54m_fck; prevents
the LCD backlight from lighting up on 2430 SDP.  Problem noted by Kevin
Hilman <khilman@mvista.com>; debugging assistance from Khasim Syed Mohammed
<x0khasim@ti.com> and Richard Woodruff <r-woodruff2@ti.com>.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/mach-omap2/clock.h

@@ -1071,7 +1071,7 @@ static struct clk dss_54m_fck = {	/* Alt clk used in power management */
 	.flags		= CLOCK_IN_OMAP242X | CLOCK_IN_OMAP243X |
 				RATE_FIXED | RATE_PROPAGATES,
 	.enable_reg	= OMAP_CM_REGADDR(CORE_MOD, CM_FCLKEN1),
-	.enable_bit	= OMAP24XX_EN_DSS2_SHIFT,
+	.enable_bit	= OMAP24XX_EN_TV_SHIFT,
 	.recalc		= &omap2_propagate_rate,
 };