arc: Add some uclibc patches

Signed-off-by: Anton Kolesov <Anton.Kolesov@synopsys.com>
arc: Support different arcitecture options

Signed-off-by: Anton Kolesov <Anton.Kolesov@synopsys.com>
arc: Set -matomic when available

Signed-off-by: Anton Kolesov <Anton.Kolesov@synopsys.com>