ARM: dts: msm: Update USB IOVA start address on sdxlemur

USB shares <iova, phy_addr> pair for tethered functionality related
buffers and TRB ring with IPA. Although USB IOVA is using atomic
property but IPA is using fastmap functionality. This results into
USB mapping also becomes fastmap. Fastmap functionality uses static
page table which increases overall memory requirement for page table.
To reduce page table related memory update USB IOVA start address
from 0x90000000 to 0x40000000 on sdxlemur.

Change-Id: I7aefa20cd05414abb585cb6a7588344ef77a08ca