Add <sys/quota.h>.

It turns out that at least the Nexus 9 kernel is built without CONFIG_QUOTA.
If we decide we're going to mandate quota functionality, I'm happy for us to
be a part of CTS that ensures that happens, but I don't want to be first, so
there's not much to test here other than "will it compile?". The strace
output looks right though.

Bug: http://b/27948821
Bug: http://b/27952303
Change-Id: If667195eee849ed17c8fa9110f6b02907fc8fc04
diff --git a/libc/arch-mips/syscalls/quotactl.S b/libc/arch-mips/syscalls/quotactl.S
new file mode 100644
index 0000000..fef336a
--- /dev/null
+++ b/libc/arch-mips/syscalls/quotactl.S
@@ -0,0 +1,19 @@
+/* Generated by gensyscalls.py. Do not edit. */
+
+#include <private/bionic_asm.h>
+
+ENTRY(quotactl)
+    .set noreorder
+    .cpload t9
+    li v0, __NR_quotactl
+    syscall
+    bnez a3, 1f
+    move a0, v0
+    j ra
+    nop
+1:
+    la t9,__set_errno_internal
+    j t9
+    nop
+    .set reorder
+END(quotactl)