BCM2708: Add core Device Tree support

Add the bare minimum needed to boot BCM2708 from a Device Tree.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

BCM2708: DT: change 'axi' nodename to 'soc'

Change DT node named 'axi' to 'soc' so it matches ARCH_BCM2835.
The VC4 bootloader fills in certain properties in the 'axi' subtree,
but since this is part of an upstreaming effort, the name is changed.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

BCM2708_DT: Correct length of the peripheral space

Use dts-dirs feature for overlays.

The kernel makefiles have a dts-dirs target that is for vendor subdirectories.

Using this fixes the install_dtbs target, which previously did not install the overlays.

BCM270X_DT: configure I2S DMA channels

Signed-off-by: Matthias Reichl <hias@horus.com>

BCM270X_DT: switch to bcm2835-i2s

I2S soundcard drivers with proper devicetree support (i.e. not linking
to the cpu_dai/platform via name but to cpu/platform via of_node)
will work out of the box without any modifications.

When the kernel is compiled without devicetree support the platform
code will instantiate the bcm2708-i2s driver and I2S soundcard drivers
will link to it via name, as before.

Signed-off-by: Matthias Reichl <hias@horus.com>

SDIO-overlay: add poll_once-boolean parameter

Add paramter to toggle sdio-device-polling
done every second or once at boot-time.

Signed-off-by: Patrick Boettcher <patrick.boettcher@posteo.de>

BCM270X_DT: Make mmc overlay compatible with current firmware

The original DT overlay logic followed a merge-then-patch procedure,
i.e. parameters are applied to the loaded overlay before the overlay
is merged into the base DTB. This sequence has been changed to
patch-then-merge, in order to support parameterised node names, and
to protect against bad overlays. As a result, overrides (parameters)
must only target labels in the overlay, but the overlay can obviously target nodes in the base DTB.

mmc-overlay.dts (that switches back to the original mmc sdcard
driver) is the only overlay violating that rule, and this patch
fixes it.

bcm270x_dt: Use the sdhost MMC controller by default

The "mmc" overlay reverts to using the other controller.

squash: Add cprman to dt

BCM270X_DT: Use clk_core for I2C interfaces