OMAP: DSS2: Check ctx loss count only when starting the first clock

When OMAP PM layer is no-op/debug, the PM layer will increment context
loss count with every call. This resulted DSS2 to restore context
whenever a clock was enabled.

This commit checks the context loss count only when the context actually
could have been lost, ie. when enabling a clock when no clocks had been
previously enabled.
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@nokia.com>

drivers/video/omap2/dss/core.c

@@ -289,9 +289,11 @@ static void dss_clk_enable_no_ctx(enum dss_clock clks)
 
 void dss_clk_enable(enum dss_clock clks)
 {
+	bool check_ctx = core.num_clks_enabled == 0;
+
 	dss_clk_enable_no_ctx(clks);
 
-	if (cpu_is_omap34xx() && dss_need_ctx_restore())
+	if (check_ctx && cpu_is_omap34xx() && dss_need_ctx_restore())
 		restore_all_ctx();
 }