[CLASS][WIC] Increase parametrization for CleaOS wks.in

Added a new variable WKS_BOOTFS_ROOTFS_PARTITION_LAYOUT to fully parametrize clea-os-image-simple.wks.in. The variable is populated starting from WKS_BOOTFS_ROOTFS_PARTITION_LAYOUT_LIST and splitting it in new lines with the | separator.

Added ad new variable WKS_BOOT_EXTRA_OPTIONS to add extra bootloader arguments.

The definition of these variables have been moved to clea-os-distro.bbclass so that layers without Seco's machines (i.e. QEMU and RaspberryPi) can use clea-os-image-simple.wks.in.

Tested on:

• Intel
• QEMU arm
• RaspberryPi by @alessandro.pecugi
• iMX by @davide.cardillo
• Rockchip by @davide.cardillo

To be tested on:

• iMX
• Mediatek
• Rockchip

Signed-off-by: Nicola Sparnacci nicola.sparnacci@seco.com