ARM: dts: msm: Add cnss sdio dsrc on msm8996 vplatform

HQX.3.0 requires sdio dsrc support on mem8996 vplatform, so add
cnss_sdio and dsrc_vreg in this device tree for this support.

Change-Id: Ieb9e9a41ea77a41a633f11d82d2ab0fa0d08bf22
Signed-off-by: Ke Huang <keh@codeaurora.org>