soc: qcom: eud: Add extcon-provider and of.h header file

Extcon header file was slit into provider and consumer apis
by this commit <176aa360> (extcon: Split out extcon
header file for consumer and provider device). Add the provider
header file in eud driver. Also add of.h header to enable
compilation of driver.

Change-Id: Ica105c3af2ff39d9a738826e94198947a4120208
Signed-off-by: Rishabh Bhatnagar <rishabhb@codeaurora.org>