Fixes the following W=1 kernel build warning(s):

 drivers/soc/tegra/fuse/speedo-tegra124.c: In function ‘tegra124_init_speedo_data’:
 drivers/soc/tegra/fuse/speedo-tegra124.c:105:38: warning: variable ‘soc_iddq_value’ set but not used [-Wunused-but-set-variable]
 drivers/soc/tegra/fuse/speedo-tegra124.c:105:22: warning: variable ‘gpu_iddq_value’ set but not used [-Wunused-but-set-variable]
 drivers/soc/tegra/fuse/speedo-tegra124.c:105:6: warning: variable ‘cpu_iddq_value’ set but not used [-Wunused-but-set-variable]

Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Jonathan Hunter <jonathanh@nvidia.com>
Cc: linux-tegra@vger.kernel.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
[treding@nvidia.com: remove unnecessary reads altogether]
Signed-off-by: Thierry Reding <treding@nvidia.com>