arm64: dts: sdm845: Add clocks and iommus to WCN3990 WLAN node

When commit 022bccb8 ("dts: arm64/sdm845: Add WCN3990 WLAN module
device node") was posted upstream no clocks were specified.  However,
when the pack was picked into the Chrome OS kernel tree (allegedly
directly from the mailing list post) it had clock properties.

I presume that the clock should be there, so let's add it.

Fixes: 022bccb8 ("dts: arm64/sdm845: Add WCN3990 WLAN module device node")
Tested-by: Sibi Sankar <sibis@codeaurora.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
[bjorn: Add also the required iommus property]
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

Signed-off-by: Andy Gross <andy.gross@linaro.org>