ANDROID: virt: geniezone: Refactoring vcpu to align with upstream v6

The used definitions related to GZVM_REG_* are below and move them to
uapi header file `gzvm.h`.
- Keep `GZVM_REG_SIZE_SHIFT` and `GZVM_REG_SIZE_MASK` so that we can
  determine the reg size.
- The other definitions related to GZVM_REG_* are used by crosvm.
- Rename the definitions to make it easy to understand.

Also removed the unused definitions related to GZVM_REG_* in
gzvm_arch.h and fixed sparse warnings.

Change-Id: I7f709f2532b95d418d22beeb4a46257afa4d92f2
Signed-off-by: kevenny hsieh <kevenny.hsieh@mediatek.com>
Signed-off-by: Yingshiuan Pan <yingshiuan.pan@mediatek.com>
Signed-off-by: Liju-Clr Chen <liju-clr.chen@mediatek.com>
Signed-off-by: Yi-De Wu <yi-de.wu@mediatek.com>
Bug: 301179926
Link: https://lore.kernel.org/all/20230919111210.19615-8-yi-de.wu@mediatek.com/