The OMAP4 L3 interconnect is split in 3 part for power saving reason.
Because of that there is no l3_main like on OMAP2 & 3 but 3 differentes
l3_main_X instances.

In the case of OMAP4, query only the l3_main_1 part. The clock and
voltage are shared across the 3 instances.
Signed-off-by: Benoit Cousson <b-cousson@ti.com>
Cc: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>