defconfig: lahaina: enable the fastrpc QGKI config option

Enable the fastrpc QGKI config option that the driver can use to
detect that it is being compiled in a QGKI kernel.

Change-Id: I6bd44bfd61e79ebe70689f326d5616b6d856c146
Acked-by: Thyagarajan Venkatanarayanan <venkatan@qti.qualcomm.com>
Signed-off-by: Himateja Reddy <hmreddy@codeaurora.org>