x86/io: Remove the unused 'bw' parameter from the BUILDIO() macro

Commit 1e8f93e1

 ("x86: Consolidate port I/O helpers") moved some
port I/O helpers to <asm/shared/io.h>, which caused the 'bw' parameter
in the BUILDIO() macro to become unused. Remove it.

Signed-off-by: Yuntao Wang <ytcoode@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20231123034911.217791-1-ytcoode@gmail.com