tools/power/x86/intel-speed-select: Always invoke isst_fill_platform_info

isst_fill_platform_info fills platform specific information.
And it is the proper place to set platform specific callbacks, as done in
next patch.

As the platform specific callbacks are needed in all cases, including
isst_print_platform_information.

The best way to achieve both is to invoke isst_fill_platform_info
unconditionally, and make isst_print_platform_information leverage the
data already filled.

No functional changes are expected.

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>