drm/radeon: fix array out-of-bounds read and write issues

There is an off-by-one bounds check on the index into arrays
table->mc_reg_address and table->mc_reg_table_entry[k].mc_data[j] that
can lead to reads and writes outside of arrays. Fix the bound checking
off-by-one error.

Addresses-Coverity: ("Out-of-bounds read/write")
Fixes: cc8dbbb4 ("drm/radeon: add dpm support for CI dGPUs (v2)")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>