drm/amdgpu: RAS EEPROM table is now in debugfs

Add "ras_eeprom_size" file in debugfs, which
reports the maximum size allocated to the RAS
table in EEROM, as the number of bytes and the
number of records it could store. For instance,

$cat /sys/kernel/debug/dri/0/ras/ras_eeprom_size
262144 bytes or 10921 records
$_

Add "ras_eeprom_table" file in debugfs, which
dumps the RAS table stored EEPROM, in a formatted
way. For instance,

$cat ras_eeprom_table
 Signature    Version  FirstOffs       Size   Checksum
0x414D4452 0x00010000 0x00000014 0x000000EC 0x000000DA
Index  Offset ErrType Bank/CU          TimeStamp      Offs/Addr MemChl MCUMCID    RetiredPage
    0 0x00014      ue    0x00 0x00000000607608DC 0x000000000000   0x00    0x00 0x000000000000
    1 0x0002C      ue    0x00 0x00000000607608DC 0x000000001000   0x00    0x00 0x000000000001
    2 0x00044      ue    0x00 0x00000000607608DC 0x000000002000   0x00    0x00 0x000000000002
    3 0x0005C      ue    0x00 0x00000000607608DC 0x000000003000   0x00    0x00 0x000000000003
    4 0x00074      ue    0x00 0x00000000607608DC 0x000000004000   0x00    0x00 0x000000000004
    5 0x0008C      ue    0x00 0x00000000607608DC 0x000000005000   0x00    0x00 0x000000000005
    6 0x000A4      ue    0x00 0x00000000607608DC 0x000000006000   0x00    0x00 0x000000000006
    7 0x000BC      ue    0x00 0x00000000607608DC 0x000000007000   0x00    0x00 0x000000000007
    8 0x000D4      ue    0x00 0x00000000607608DD 0x000000008000   0x00    0x00 0x000000000008
$_

Cc: Alexander Deucher <Alexander.Deucher@amd.com>
Cc: Andrey Grodzovsky <Andrey.Grodzovsky@amd.com>
Cc: John Clements <john.clements@amd.com>
Cc: Hawking Zhang <Hawking.Zhang@amd.com>
Cc: Xinhui Pan <xinhui.pan@amd.com>
Signed-off-by: Luben Tuikov <luben.tuikov@amd.com>
Acked-by: Alexander Deucher <Alexander.Deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>