device-samsung-a6lte: fix Bluetooth init.d script

It seems that bootmac's commandline argument parsing was rewritten, and it no longer accepts multiple flags in one argument. Change the invocation to work around that.

The zstd compression also broke hciattach's firmware loading (and there's no easy way to fix that one), but the chip seems to still start up without loading firmware, so I'm too lazy to fix that.