defconfig: msm: Enable dynamic minors for sdxprairie perf

Sound card registration fails, while trying to register
sound card without the dynamic minor configuration in the
perf defconfig.
To fix this, Enable the dynamic minors config from
sdxprairie-perf defconfig.

CRs-Fixed: 2446772
Change-Id: I44893e598bd66befa300090152543dd60babc430
Signed-off-by: Anurag Chouhan <achouhan@codeaurora.org>