ANDROID: Address flaky behaviour in genksyms affecting CRC stability.

Commit 1278a5bf ("ANDROID: ABI: Added symbols for allwinner")
introduced ehci_* symbols to the symbol list. Due to a bug in genksyms,
the CRC of those is not resilient to whether other symbols are exported
as well. In particular, the CRC changes with the export/trimming of
ehci_handshake. Add an artificial symbol list to contain ehci_handshake
to make this stable.

Also update the ABI representation accordingly:

1 Added function:

  [A] 'function int ehci_handshake(ehci_hcd*, void*, u32, u32, int)'

Bug: 167230325
Signed-off-by: Matthias Maennich <maennich@google.com>
Change-Id: I58d3a93f49e70a66f34b66f9f8784b9c19c5a58b