defconfig: 8916: enable adsp loader flag in perf defconfig.

Enable MSM_ADSP_LOADER flag in perf def config to allow
PIL loading of modem and to retain vote from audio at boot time.

CRs-Fixed: 644286
Change-Id: I381b6b77793fba0e63cfdc4166a3c393c64d13e3
Signed-off-by: Santosh Mardi <gsantosh@codeaurora.org>