omap: Fix 3630 mux errors

3630 has more mux signals than 34xx. The additional pins
exist in omap36xx_cbp_subset, but are not initialized
as the superset is missing these offsets. This causes
the following errors during the boot:

mux: Unknown entry offset 0x236
mux: Unknown entry offset 0x22e
mux: Unknown entry offset 0x1ec
mux: Unknown entry offset 0x1ee
mux: Unknown entry offset 0x1f4
mux: Unknown entry offset 0x1f6
mux: Unknown entry offset 0x1f8
mux: Unknown entry offset 0x1fa
mux: Unknown entry offset 0x1fc
mux: Unknown entry offset 0x22a
mux: Unknown entry offset 0x226
mux: Unknown entry offset 0x230
mux: Unknown entry offset 0x22c
mux: Unknown entry offset 0x228

Fix this by adding the missing offsets to omap3 superset.
Note that additionally the uninitialized pins need to be
skipped on 34xx.

Based on an earlier patch by Allen Pais <allen.pais@ti.com>.

Reported-by: Allen Pais <allen.pais@ti.com>
Signed-off-by: Allen Pais <allen.pais@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>