Expose sclk (gfx clock) and mclk (memory clock) via
hwmon compatible interface. hwmon does not actually
formally specify a frequency type attribute, but these
are compatible with the format of the other attributes
exposed via hwmon. Units are hertz.
freq1_input - GPU gfx/compute clock in hertz
freq2_input - GPU memory clock in hertz (dGPU only)
Reviewed-by: Evan Quan <evan.quan@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>