i2c-designware: Fix PCI core warning on suspend/resume

PCI core warns if the legacy PM and new PM functions are
present. Update the driver to only use the new power management
framework.

This patch fixes the following warning seen during suspend/resume:

<7>[   24.193850] i2c-designware-pci 0000:08:13.0: suspend
<4>[   24.193866] ------------[ cut here ]------------
<4>[   24.193892] WARNING: at drivers/pci/pci-driver.c:605 pci_has_legacy_pm_support+0x48/0x4d()
<4>[   24.193925] Hardware name: OakTrail
<4>[   24.193936] Modules linked in:
<4>[   24.193958] Pid: 2834, comm: kworker/u:22 Tainted: G        W   2.6.36greenridge-01402-gc8047e6 #171
<4>[   24.193974] Call Trace:
<4>[   24.193999]  [<c1033a93>] warn_slowpath_common+0x66/0xc2
<4>[   24.194025]  [<c1164143>] ? pci_has_legacy_pm_support+0x48/0x4d
<4>[   24.194052]  [<c1033afe>] warn_slowpath_null+0xf/0x13
<4>[   24.194079]  [<c1164143>] pci_has_legacy_pm_support+0x48/0x4d
<4>[   24.194106]  [<c11643ff>] pci_pm_suspend+0x22/0x154
<4>[   24.194131]  [<c11643dd>] ? pci_pm_suspend+0x0/0x154
<4>[   24.194156]  [<c11e8a7a>] pm_op+0x3e/0x95
<4>[   24.194182]  [<c11e931d>] __device_suspend+0x12e/0x194
<4>[   24.194208]  [<c11e974d>] ? dpm_drv_timeout+0x0/0x47
<4>[   24.194237]  [<c11e9729>] async_suspend+0x16/0x3a
<4>[   24.194265]  [<c104de8e>] async_run_entry_fn+0x97/0x135
<4>[   24.194291]  [<c1043c34>] process_one_work+0x1c9/0x2db

Signed-off-by: Octavian Purdila <octavian.purdila@intel.com>
Signed-off-by: Dirk Brandewie <dirk.brandewie@gmail.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>