platform: tegra: remove redundant irq.c

platform: tegra: remove redundant irq.c

the irq.c in drivers/platform/tegra was created when
its functionality didn't exist in arm64, now it's supported
in arch/arm64/kernel, so this file becomes redundant and
unused, remove it.

Change-Id: I6b662ce169319862dc1e2b5ed1fd8570ee2cda37
Signed-off-by: Bo Yan <byan@nvidia.com>
Reviewed-on: http://git-master/r/487101
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Peng Du <pdu@nvidia.com>