setup_sdcard.sh: partition is not always 1 & 2

Signed-off-by: Robert Nelson <robertcnelson@gmail.com>
setup_sdcard.sh: drop --swap_file

Signed-off-by: Robert Nelson <robertcnelson@gmail.com>
setup_sdcard.sh: drop btrfs support, ill add it back, after u-boot gets support

Signed-off-by: Robert Nelson <robertcnelson@gmail.com>
setup_sdcard.sh: cleanup/bikesheeding

Signed-off-by: Robert Nelson <robertcnelson@gmail.com>