add navi14 umd pstate peak clock support.

NAVI14_UMD_PSTATE_PEAK_XT_GFXCLK   1670 MHz
NAVI14_UMD_PSTATE_PEAK_XTM_GFXCLK  1448 MHz
NAVI14_UMD_PSTATE_PEAK_XLM_GFXCLK  1181 MHz
NAVI14_UMD_PSTATE_PEAK_XTX_GFXCLK  1717 MHz
NAVI14_UMD_PSTATE_PEAK_XL_GFXCLK   1448 MHz
Signed-off-by: Kevin Wang <kevin1.wang@amd.com>
Reviewed-by: Kenneth Feng <kenneth.feng@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>