backports: add kernel base requirement of 3.5 to IR_IMG

backports: add kernel base requirement of 3.5 to IR_IMG

IR_IMG is a new driver added by James via 160a8f8a and letter
integrated into the build via commit 54b29120 as of linux-next
tag next-20140320 which may make it to Linux through v3.15. This
new driver makes use of devm_clk_get() but this was added via
a8a97db9 and that get merged as of v3.5. It seems we can easily
backport a8a97db9 but these days I'm starting to leave this up to the
folks interested in the drivers to choose / participate and only
they would know if this is worth it. Is 3.5 a good starting point
kernel to require for drivers which depend on the new clock APIs?

mcgrof@ergon ~/linux-next (git::master)$ git describe --contains a8a97db9
v3.5-rc1~183^2~2

Cc: James Hogan <james.hogan@imgtec.com>
Cc: Mauro Carvalho Chehab <m.chehab@samsung.com>
Cc: Mark Brown <broonie@linaro.org>
Signed-off-by: Luis R. Rodriguez <mcgrof@do-not-panic.com>