ARM: OMAP2+: Drop legacy platform data for omap4 gpu

I've tested that the interconnect target module enables and idles
just fine when probed with ti-sysc with PM runtime control via sys:

# echo on > $(find /sys -name control | grep \/5601)
# rwmem 0x56000024
0x56000024 = 0x00010200		# SGX540 CORE_REVISION
# echo auto > $(find /sys -name control | grep \/5601)
# rwmem 0x56000024
And when idled, it will produce "Bus error" as expected.

Cc: Adam Ford <aford173@gmail.com>
Cc: Filip Matijević <filip.matijevic.pz@gmail.com>
Cc: "H. Nikolaus Schaller" <hns@goldelico.com>
Cc: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
Cc: moaz korena <moaz@korena.xyz>
Cc: Merlijn Wajer <merlijn@wizzup.org>
Cc: Paweł Chmiel <pawel.mikolaj.chmiel@gmail.com>
Cc: Philipp Rossak <embed3d@gmail.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>