drm/amd/display: Fix spelling mistake: "dram_clk_chanage" -> "dram_clk_change"

There is a spelling mistake in the struct field dram_clk_chanage. Fix it.

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: Hamza Mahfooz <hamza.mahfooz@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>