arm64: dts: qcom: pm8150l: add spmi-flash-led node

Add a node describing the flash block found on pm8150l.

Signed-off-by: Danila Tikhonov <danila@jiaxyga.com>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230321182319.24958-1-danila@jiaxyga.com