OMAP3: id: remove identification codes that only correspond to marketing names

The OMAP3505/AM3505 appears to be based on the same silicon as the
OMAP3517/AM3517, with some features disabled via eFuse bits.  Follow
the same practice as OMAP3430 and identify these devices internally as
part of the OMAP3517/AM3517 family.

The OMAP3503/3515/3525/3530 chips appear to be based on the same silicon
as the OMAP3430, with some features disabled via eFuse bits.  Identify
these devices internally as part of the OMAP3430 family.

Remove the old OMAP35XX_CLASS, which actually covered two very different
chip families.  The OMAP3503/3515/3525/3530 chips will now be covered by
OMAP343X_CLASS, since the silicon appears to be identical.  For the
OMAP3517/AM3517 family, create a new class, OMAP3517_CLASS.

Thanks to Tony Lindgren <tony@atomide.com> for some help with the second
revision of this patch.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Sanjeev Premi <premi@ti.com>
Cc: Tony Lindgren <tony@atomide.com>
Tested-by: Igor Grinberg <grinberg@compulab.co.il>
Tested-by: Abhilash Koyamangalath <abhilash.kv@ti.com>