phy: phy-core: increment refcounting variables only on 'success'

Increment 'init_count' only if the 'init' callback succeeded and decrement
'init_count' only if the 'exit' callback succeded. Increment 'power_count'
only if 'power_on' callback succeded and if it failed disable the clocks using
phy_pm_runtime_put_sync(). Also decrement 'power_count' only if 'power_off'
callback succeded and if it failed do not disable the clocks.

Reported-by: George Cherian <george.cherian@ti.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>