defconfig: msm8994: Sync the regular and perf-defconfigs

The DM_VERITY and SiLabs Radio support options were enabled
in the msm8994_defconfig but not in the -perf variant.
Update msm8994-perf_defconfig to be in sync with
msm8994_defconfig.

Change-Id: I69296f99424533cc591046420cbf2fc932f75f0c
Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>