redpine: set low power rx/tx mode for wifi

2 jobs for redpine_20210824 in 63 minutes and 27 seconds (queued for 1 second)
latest
Status Job ID Name Coverage
  Build
passed #363663
librem5
build:aarch64

00:20:02

passed #363664
librem5:arm64
build:deb

01:03:27