Automatically compile the script and add to NAND and SD packages.

This is needed by mkimage script.

This resolves USB-related issues for HD18Q.

This allows to build for many devices with common system and kernel image,
with different file system contents and device trees.

This forces to use a common kernel configuration to prevent future mistakes.

This reverts commit 083dd712.

Also make script arch-independent (for future use with arm64).

- Delete unneeded stmmac entry from HD18Q and MXQ
- Update m201C_* with source from downloaded from Baidu

Mtools is used to format and copy files to vfat partition.
Populatefs is used to copy files to ext4 partition.

Tested on imx6 with u-boot, Generic with BIOS and EFI boot.

To avoid messing around with ext4 partition we could also provide "empty" disk image file. Both partitions would be already formatted and storage partition would already contain resize file. Then mkimage script would only copy kernel, system, bootloader files and install bootloader.
But current approach is more flexible for future use.

This reverts commit cff56c00.

m201C_1G is experimental, derived from m201C_512M and m201_1G

With multi-dtb support, this option is no longer needed

To keep in line with upstream.

- add 'quiet' cmdline parameter to limit console output
- don't build Android drivers
- disable HWMON

Helps with some older TVs.

Old ethernet driver fixes MAC address reading for some devices.
It needs to be loaded as a module to be able to read MAC from NAND/eMMC.

scripts/image: Create zipped package for uenv-update SD card and add uenv update script to NAND installation package