if_ether: Remove the definition of ETH_P_MAP

This is already defined in upstream kernel as a non NON DIX type
so remove this custom definition.

CRs-Fixed: 2086060
Change-Id: I71bb321d6a2c9091db9a454be1d7b80b87b92ed5
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>