tree 1ff53d130a8c168354b00f88aa2648754d7209a4
parent 6d8d8d63c46bcfbf0427504ada524dfaeec91f54
author Tom Tung <shes050117@gmail.com> 1678826644 +0800
committer Tom Tung <shes050117@gmail.com> 1679294378 +0800

dimm: use size to determine if DIMM is present and functional

Currently, we are using "NO DIMM" in dimmManufacturer to determine if
there is a DIMM sensor or not. However, it's "Unknown" in an AMD machine
we are testing.

Looking into SMBIOS spec (DSP0134_3.3.0), it looks like using size to
determine if DIMM is present and functional is a better option.

Tested:
Check an Intel CPU machine and the Present is true when DIMM is there
and false when it's not:
```
busctl introspect xyz.openbmc_project.Smbios.MDR_V2 \
    /xyz/openbmc_project/inventory/system/chassis/motherboard/dimm0 \
    xyz.openbmc_project.Inventory.Item
NAME                               TYPE      SIGNATURE RESULT/VALUE
FLAGS
.Present                           property  b         true
emits-change writable
.PrettyName                        property  s         ""
emits-change writable

busctl introspect xyz.openbmc_project.Smbios.MDR_V2 \
    /xyz/openbmc_project/inventory/system/chassis/motherboard/dimm1 \
    xyz.openbmc_project.Inventory.Item
NAME                               TYPE      SIGNATURE RESULT/VALUE
FLAGS
.Present                           property  b         false
emits-change writable
.PrettyName                        property  s         ""
emits-change writable
```
Check an AMD machine and it works fine with a bad DIMM and a good DIMM:
```
busctl introspect
xyz.openbmc_project.Smbios.MDR_V2
/xyz/openbmc_project/inventory/system/chassis/motherboard/dimm0
xyz.openbmc_project.Inventory.Item
NAME                               TYPE      SIGNATURE RESULT/VALUE
FLAGS
.Present                           property  b         false
emits-change writable
.PrettyName                        property  s         ""
emits-change writable

busctl introspect
xyz.openbmc_project.Smbios.MDR_V2
/xyz/openbmc_project/inventory/system/chassis/motherboard/dimm1
xyz.openbmc_project.Inventory.Item
NAME                               TYPE      SIGNATURE RESULT/VALUE
FLAGS
.Present                           property  b         true
emits-change writable
.PrettyName                        property  s         ""
emits-change writable
```

Change-Id: If6ea55f35b4af3225c4a07de481d930fa461b3e7
Signed-off-by: Tom Tung <shes050117@gmail.com>