Add `.rv32` on rv32_zbs and rv32_zbb instructions (#220)

* Add .rv32 on rv32_zbs instructions

to be consistent with slli, srli, and srai.

Signed-off-by: Hiroo HAYASHI <24754036+hirooih@users.noreply.github.com>

* Add .rv32 on rv32_zbb instructions

- zext.h.rv32, rev8.rv32, and rori.rev32

-  rev8.rv32, and rori.rev32 are also aliased in rv32_{zk,zkn,zks,zbkb}
  - only rv32_zks is shown in the extension field

Signed-off-by: Hiroo HAYASHI <24754036+hirooih@users.noreply.github.com>

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Signed-off-by: Hiroo HAYASHI <24754036+hirooih@users.noreply.github.com>