[AVR32] Don't enable clocks with no users

Bring the code that sets the initial PM clock masks in line with the
comment preceding it by only enabling clocks that have users != 0.
Fix SM clock definition and avr32_hpt_init() so that the SM and TC0
clocks keep ticking.

Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
diff --git a/arch/avr32/mach-at32ap/time-tc.c b/arch/avr32/mach-at32ap/time-tc.c
index 7ac0e94..e3070bd 100644
--- a/arch/avr32/mach-at32ap/time-tc.c
+++ b/arch/avr32/mach-at32ap/time-tc.c
@@ -135,6 +135,7 @@
 		pr_debug("timer: could not get clk: %ld\n", PTR_ERR(pclk));
 		goto out_error;
 	}
+	clk_enable(pclk);
 
 	regs = platform_get_resource(&at32_systc0_device, IORESOURCE_MEM, 0);
 	if (!regs) {