unixodbc: fix cross-compile drivers

build odbc_config for host so drivers may use it to figure out build
details, patch odbc_config to return target specific values from
unixodbc_conf.h.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

libs/unixodbc/patches/100-cross-compile-odbc-config.patch

@@ -0,0 +1,36 @@
+--- a/exe/odbc-config.c
++++ b/exe/odbc-config.c
+@@ -40,6 +40,33 @@
+ #include <unistd.h>
+ #endif
+ 
++#ifdef USE_UNIXODBC_CONF_H
++
++#ifdef HAVE_UNISTD_H
++#undef HAVE_UNISTD_H
++#endif
++#ifdef HAVE_PWD_H
++#undef HAVE_PWD_H
++#endif
++#ifdef HAVE_SYS_TYPES_H
++#undef HAVE_SYS_TYPES_H
++#endif
++#ifdef HAVE_LONG_LONG
++#undef HAVE_LONG_LONG
++#endif
++#ifdef ODBCINT64
++#undef ODBCINT64
++#endif
++#ifdef UODBCINT64
++#undef UODBCINT64
++#endif
++#ifdef SIZEOF_LONG_INT
++#undef SIZEOF_LONG_INT
++#endif
++
++#include <unixodbc_conf.h>
++#endif
++
+ #include <sql.h>
+ 
+ static void usage( void )