ARM: OMAP3: clock data: get rid of unused USB host clock aliases and dummies

We don't need multiple aliases for the OMAP USB host clocks and neither
the dummy clocks so remove them.

CC: Paul Walmsley <paul@pwsan.com>
CC: Rajendra Nayak <rnayak@ti.com>
CC: Benoit Cousson <b-cousson@ti.com>
CC: Mike Turquette <mturquette@linaro.com>
Signed-off-by: Roger Quadros <rogerq@ti.com>
[paul@pwsan.com: updated against v3.10-rc4]
Signed-off-by: Paul Walmsley <paul@pwsan.com>