ARM: imx: fix .is_enabled() of shared gate clock

Commit 63288b72 ("ARM: imx: fix shared gate clock") attempted to fix
an issue with particular enable/disable sequence from two shared gate
clocks.  But unfortunately, while it partially fixed the issue, it also
did something wrong in .is_enabled() function hook.  In case of shared
gate, the function shouldn't really query the hardware state via
share_count, because the function is trying to query the enabling state
of the clock in question, not the hardware state which is shared by
multiple clocks.

Fix the issue by returning the enable_count of the clock itself which is
maintained by clock core, in case it's a clock sharing hardware gate
with others.  As the result, the initialization of share_count per
hardware state is not needed now.  So remove it.

Reported-by: Fabio Estevam <fabio.estevam@freescale.com>
Fixes: 63288b72 ("ARM: imx: fix shared gate clock")
Cc: <stable@vger.kernel.org>
Signed-off-by: Shawn Guo <shawn.guo@freescale.com>
Tested-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Olof Johansson <olof@lixom.net>