[AMDGPU] Fix maximum physical LDS reporting for gfx6 (#223185)
Reference:
https://docs.amd.com/api/khub/documents/VeItSxvoJNzy28rl~JwEAQ/content#page=77
> “The maximum LDS allocation size for a work-group is still 32 kB,
however each compute unit has a total of 64 kB of LDS.”
Reference:
https://docs.amd.com/api/khub/documents/J4foK5jvufN9rTHf_DlCPw/content#page=22
> “Each compute unit has a 64 kB of Local Data Share (LDS) memory
space…”
> “Each workgroup can allocate up to 32 kB of this space, and can read
and write any portion of the LDS space allocated to it.”