ARM: dts: qcom: Add Samsung Galaxy Express support

Add a very basic device tree file for the Samsung Galaxy Express SGH-I437.
Currently, the following things work: UART, eMMC, SD Card, and USB.

Signed-off-by: Rudraksha Gupta <guptarud@gmail.com>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230607050025.86636-5-guptarud@gmail.com