ARM: davinci: da850: Fix pwm name matching

This fixes pwm name matching for DA850 familiy devices. When using device
tree, the da850_auxdata_lookup[] table caused pwm devices to have the exact
same name, which caused errors when trying to register the devices.

We cannot have multiple entries for the same clock in in da850_clks[], so
we have added child clocks to the EHRPWM and ECAP LPSC clocks so that each
PWM device will have its own clock for proper name matching.

Signed-off-by: David Lechner <david@lechnology.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>