arm64: dts: qcom: sdm845-xiaomi-beryllium: change firmware path and use mbn format

arm64: dts: qcom: sdm845-xiaomi-beryllium: change firmware path and use mbn format

The "qcom/sdm845/" path conflicts with db845c's firmware that are
present in the linux-firmware package. Xiaomi uses their own signed
firmware for Poco F1 and can't use the db845c's firmware. So let's
use "qcom/sdm845/beryllium/" to distinguish Poco F1's firmware files.

For easier handling and packaging, the mdt+bXX files are squashed
using Bjorn Andersson's pil-squasher tool from this link:
https://github.com/andersson/pil-squasher

Signed-off-by: Joel Selvaraj <jo@jsfamily.in>
Reviewed-by: Caleb Connolly <caleb@connolly.tech>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/BY5PR02MB700966DEE6F6044EBEB5B892D91F9@BY5PR02MB7009.namprd02.prod.outlook.com