libgpgme: fix build on MIPS with older kernel headers

MIPS N64 ABI has been missing getdents64 wire up until kernel version
3.10. Disable use of getdents on older kernels.

Fixes:
http://autobuild.buildroot.net/results/961/9619062ce6642ae4121d7debb3b4c632c88723d5/

Cc: Vicente Olivert Riera <Vincent.Riera@imgtec.com>
Cc: Philipp Claves <claves@budelmann-elektronik.com>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/libgpgme/libgpgme.mk

@@ -35,4 +35,9 @@ LIBGPGME_CONF_ENV += LIBS="-largp" ac_cv_type_error_t=yes
 LIBGPGME_DEPENDENCIES += argp-standalone
 endif
 
+# MIPS N64 (re)introduced getdents64 in kernel version 3.10
+ifeq ($(BR2_MIPS_NABI64)x$(BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_10),yx)
+LIBGPGME_CONF_OPTS += --disable-linux-getdents
+endif
+
 $(eval $(autotools-package))