speakup: replace utils' u_char with unsigned char

drivers/accessibility/speakup/utils.h will be used to compile host tool
to generate metadata.

"u_char" is a non-standard type, which is defined to "unsigned char"
on glibc but not defined by some libc, e.g. musl.

Let's replace "u_char" with "unsigned char"

Signed-off-by: Đoàn Trần Công Danh <congdanhqx@gmail.com>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Cc: stable <stable@kernel.org>
Link: https://lore.kernel.org/r/b75743026aaee2d81efe3d7f2e8fa47f7d0b8ea7.1665736571.git.congdanhqx@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

speakup: Generate speakupmap.h automatically

speakupmap.h was not actually intended to be source code, speakupmap.map
is.

This resurrects the makemapdata.c and genmap.c tools to generate
speakupmap.h automatically from the input and speakup headers, and the
speakupmap.map keyboard mapping source file.

Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Link: https://lore.kernel.org/r/20220612172244.il3siyq7ueqnvah5@begin
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>