spi: exynos5433-isp: Fix doubled clock disable on suspend

spi: exynos5433-isp: Fix doubled clock disable on suspend

This patch came from the commit 9d7fd21acb20 ("spi/s3c64xx: Fix doubled
clock disable on suspend") and the commit 4fcd9b9e06d4 ("spi: s3c64xx:
simplify suspend / resume handlers").

Fix doubled clock disable and unprepare during PM suspend which triggered
the warnings:

[   24.258574] WARNING: CPU: 0 PID: 326 at drivers/clk/clk.c:1010 clk_core_disable+0x90/0x14c()
[   24.258580] Modules linked in:
[   24.258589] CPU: 0 PID: 326 Comm: deviced Not tainted 4.1.0-01299-g70114f2-dirty #26
[   24.258592] Hardware name: Samsung TM2 board (DT)
[   24.258595] Call trace:
[   24.258605] [<ffffffc000089f34>] dump_backtrace+0x0/0x124
[   24.258610] [<ffffffc00008a068>] show_stack+0x10/0x1c
[   24.258618] [<ffffffc000a36ed0>] dump_stack+0x78/0xbc
[   24.258624] [<ffffffc00009acc8>] warn_slowpath_common+0x9c/0xd4
[   24.258628] [<ffffffc00009adc0>] warn_slowpath_null+0x14/0x20
[   24.258632] [<ffffffc000748e80>] clk_core_disable+0x8c/0x14c
[   24.258636] [<ffffffc0007493ec>] clk_disable+0x28/0x40
[   24.258644] [<ffffffc000529164>] s3c64xx_spi_suspend+0x3c/0x70
[   24.258652] [<ffffffc0004d7938>] platform_pm_suspend+0x20/0x50
[   24.258659] [<ffffffc0004e1b10>] dpm_run_callback+0x4c/0x190
[   24.258664] [<ffffffc0004e2b34>] __device_suspend+0xf4/0x380
[   24.258669] [<ffffffc0004e4738>] dpm_suspend+0x128/0x35c
[   24.258674] [<ffffffc0004e4e74>] dpm_suspend_start+0x68/0x78
[   24.258681] [<ffffffc0000e269c>] suspend_devices_and_enter+0xb8/0x838
[   24.258685] [<ffffffc0000e319c>] pm_suspend+0x380/0x5d8
[   24.258690] [<ffffffc0000e16d4>] state_store+0x7c/0xf4
[   24.258697] [<ffffffc000376a74>] kobj_attr_store+0x10/0x24
[   24.258705] [<ffffffc0002164d4>] sysfs_kf_write+0x3c/0x50
[   24.258710] [<ffffffc00021596c>] kernfs_fop_write+0xbc/0x180
[   24.258718] [<ffffffc0001aa2e8>] __vfs_write+0x28/0x10c
[   24.258722] [<ffffffc0001aac00>] vfs_write+0x8c/0x16c
[   24.258726] [<ffffffc0001ab518>] SyS_write+0x40/0xa0

The clocks may be already disabled before suspending. Check PM runtime
suspend status and disable clocks only if device is not suspended.
During resume do not enable the clocks if device is runtime suspended.

Change-Id: I194a5d458744086998b82602146648d34ff7050a
Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>