fbdev: simplefb: add init through platform_data

If we create proper platform-devices in x86 boot-code, we can use simplefb
for VBE or EFI framebuffers, too. However, there is normally no OF support
so we introduce a platform_data object so x86 boot-code can pass the
parameters via plain old platform-data.

This also removes the OF dependency as it is not needed. The headers
provide proper dummies for the case OF is disabled.

Furthermore, we move the FORMAT-definitions to the common platform header
so initialization code can use it to transform "struct screen_info" to
the right format-name.

Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Link: http://lkml.kernel.org/r/1375445127-15480-2-git-send-email-dh.herrmann@gmail.com


Reviewed-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>