device/*-asus-{grouper,tilapia}: various enhancements

This patchset solves:

• update kernel (add SMB347 driver, add thermal support, fix Epiphany browser etc.)
• update firmware to support grouper (symlink, file is identical)
• moves grouper into tilapia (since right now it supports only tilapia properly)
• creates new grouper package for grouper (non-GSM version)

Supersede: !1003

• v3: added findutils to make kernel compilation without warnings
• v4: bumped kernel by one fix commit accidentally missed before + naming fix