RAS support capability needs to be updated on top of different
memeory ECC enablement, and remove redundant memory ecc check
in gmc module for vega20 and arcturus.

v2: check HBM ECC enablement and set ras mask accordingly.
v3: avoid to invoke atomfirmware interface to query twice.
Suggested-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Guchun Chen <guchun.chen@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>