ARM: OMAP: remove the sti console workaround

The sti console workaround uses the OMAP custom tags.
Those tags are not used in upstream kernel and therefore the workaround
never fires on upstream kernels.
Remove the sti console workaround tags part.
This leaves the workaround functional part intact so can be reused if
needed.

Signed-off-by: Igor Grinberg <grinberg@compulab.co.il>
Signed-off-by: Tony Lindgren <tony@atomide.com>