Build system uses separate build directory for kernels now, but
beaglebone's linux-mainline recipes only works when built from
the source directory.

Change-Id: If18b47a31daf2dc4e4e5c1aab84978113b535ec7
Reviewed-by: aavit <eirik.aavitsland@theqtcompany.com>

Build perf with DWARF unwinding support. Kernels older then 3.14
need to be patched to add ARM support. Kernels for tibidabo (3.0)
and imx53 (2.6) are too old and would require more patches to be
backported, so they are left without unwinding support.

RPi needed extra layer to modify the kernel recipe, and linux-imx
recipe was renamed so that it doesn't conflict with older tibidabo
kernel recipe.

Change-Id: Ic8331f8feeace67b32a5ce99ffd3fda517d595d1
Reviewed-by: Andy Nichols <andy.nichols@theqtcompany.com>
Reviewed-by: Ulf Hermann <ulf.hermann@theqtcompany.com>

The boneblack u-boot config adds support for environment storage
in eMMC. Kernel image type is changed to zImage to reflect which
is what the u-boot defaults to. For older versions of u-boot that
try to use uImage, set extra u-boot arguments in uEnv.txt.

Change-Id: I98bd37db41a7c80a1aa75e9ae53c1e00589fde64
Reviewed-by: Andy Nichols <andy.nichols@digia.com>
Reviewed-by: Kalle Viironen <kalle.viironen@digia.com>

Create new layer for recipes and files that required only when
meta-beagleboard layer is used. For now, the bblayers.conf
template still includes the new layer as well.

Change-Id: I5e50067b8b6c7d480d3808a24e8acc2ace07b04b
Reviewed-by: Eirik Aavitsland <eirik.aavitsland@digia.com>