[Libva] [intel-driver] check that intel-gen4asm tool is actually present

[Xiang, Haihao]

Applied

Thanks
Haihao

> intel-gen4asm tool has to be present on the host tools so that
> it can actually be used. Cross compiling shows problems when the
> gpu-tools version is met but the tool is not available on the PATH
> 
> So, first check that the tool is available and later check for version
> before defining HAVE_GEN4ASM.
> 
> Signed-off-by: Daniel Charles <daniel.charles at intel.com>
> ---
>  configure.ac | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/configure.ac b/configure.ac
> index 86c2b40..a588106 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -77,8 +77,9 @@ AC_SUBST(LIBDRM_VERSION)
>  
>  dnl Check for gen4asm
>  PKG_CHECK_MODULES(GEN4ASM, [intel-gen4asm >= 1.5], [gen4asm=yes], [gen4asm=no])
> -AM_CONDITIONAL(HAVE_GEN4ASM, test x$gen4asm = xyes)
>  AC_PATH_PROG([GEN4ASM], [intel-gen4asm])
> +AS_IF([test "x$GEN4ASM" = "x" ], [AM_CONDITIONAL(HAVE_GEN4ASM, false)],
> +    [AM_CONDITIONAL(HAVE_GEN4ASM, [test x$gen4asm = xyes])])
>  
>  dnl Check for VA-API
>  PKG_CHECK_MODULES(LIBVA_DEPS,     [libva >= va_api_version])