drm/amd/powerplay: fix misspelling in header guard
In smu7_clockpowergating.h, the #ifndef statement which prevents
multiple inclusions of the header file uses _SMU7_CLOCK_POWER_GATING_H_
but the following #define statement uses _SMU7_CLOCK__POWER_GATING_H_.
Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Nicolas Iooss