soc: Introduce drivers/soc place-holder for SOC specific drivers

Based on earlier thread "https://lkml.org/lkml/2013/10/7/662" and
discussion at Kernel Summit'2013, it was agreed to create
'driver/soc' for drivers which are quite SOC specific.

Further discussion on the subject is in response to
the earlier version of the patch is here:
	http://lwn.net/Articles/588942/

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Kumar Gala <galak@codeaurora.org>
Cc: Paul Walmsley <paul@pwsan.com>
Cc: Olof Johansson <olof@lixom.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Sandeep Nair <sandeep_n@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Kumar Gala <galak@codeaurora.org>