clk: bcm2835: Fix PLL poweron

In poweroff, we set the reset bit and the power down bit, but only
managed to unset the reset bit for poweron.  This meant that if HDMI
did -EPROBE_DEFER after it had grabbed its clocks, we'd power down the
PLLH (that had been on at boot time) and never recover.

Signed-off-by: Eric Anholt <eric@anholt.net>
Fixes: 41691b88

 ("clk: bcm2835: Add support for programming the audio domain clocks")
Cc: stable@vger.kernel.org
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>