u-boot: unbreaks u-boot for all other layers

The u-boot bbappend broke u-boot builds for other layers due to
replacing the SRC_URI without any overrides.

Fix this by using a namespaced recipe for the at91 u-boot.

This should fix https://github.com/linux4sam/meta-atmel/issues/8

Signed-off-by: Koen Kooi <koen@dominion.thruhere.net>
linux-yocto-custom: avoid PV going backwards on updates

Using SRCREV instead of SRCPV in PV will lead to errors like:

	ERROR: QA Issue: Package version for package kernel-module-lib80211-crypt-wep went backwards which would break package feeds from (0:3.10+ea25eb8a3ac9fcebc6c0d3b1c8e0c1223684d331-r4.1 to 0:3.10+68f2c28207fbc081f7be75fc01aca4827aa4a9f1-r5.1)

Which breaks upgrade paths.

Signed-off-by: Koen Kooi <koen@dominion.thruhere.net>
sama5d3_xplained.conf: remove IMAGE_POSTPROCESS_COMMAND

The method is only defined in the demo images, so trying to build any
other image will result in:

/build/v2013.12/build/tmp-angstrom_v2013_12-eglibc/work/sama5d3_xplained-angstrom-linux-gnueabi/systemd-image/1.0-r0/temp/run.do_rootfs.14199:
line 436: sama5d3_xplained_rootfs_postprocess: command not found

Signed-off-by: Koen Kooi <koen@dominion.thruhere.net>
Update README to properly reference dependencies

OE layers depend on upstream OE layers, not downstream distro forks of the layers.

The instructions still reference poky, but since they don't work anyway due to other bugs in this layer I've left them alone.

Signed-off-by: Koen Kooi <koen@dominion.thruhere.net>
linux-yocto-custom: update sama5d3_xplained defconfig

This makes it work with modern userspace:

* enable CONFIG_FHANDLE for recent udev versions
* disable SYSFS_DEPRECATED to work with udev versions released after 2011
* enable IKCONFIG_PROC to have access to /proc/config.gz
* increase dmesg buffer to 64KiB
* zero HOTPLUG_HELPER_PATH to work with udev versions more recent than 141
* enable PWM sysfs nodes
* enable AUTOFS4 for systemd
* enable FUSE

Signed-off-by: Koen Kooi <koen@dominion.thruhere.net>
sama5d3_explained: add udc and g-serial to MACHINE_ESSENTIAL_RRECOMMENDS

This will ensure images will pick them up. The 'kernel-module-u-serial'
is added to solve a bug in the kernel.bbclass dependency code. The
g_serial module needs it, but doesn't depend on it.

Signed-off-by: Koen Kooi <koen@dominion.thruhere.net>
linux-yocto-custom: enable PRINTK_TIME for sama5d3_xplained

This will add a timestamp to each line of kernel output.

Signed-off-by: Koen Kooi <koen@dominion.thruhere.net>