site/common-linux: coreutils: get the uptime program to work

coreutils configure script needs to know whether /proc/uptime is
available, but this is not possible in a cross-compilation
context. This leads to an uptime program that fails to work on the
target, as it has been compiled without /proc/uptime reading support.

This commit fixes that by telling coreutils at configure time that
/proc/uptime will be available on the target (which seems to be a
reasonable assumption on Linux systems).

This commit is made with great inspiration from Thomas Petazzoni's
patch to buildroot to fix the same issue.

(From OE-Core rev: 199b661c0699eb31df5bc73f2e3dce6a2db4585d)

Signed-off-by: Sean Nyekjaer <sean.nyekjaer@prevas.dk>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/site/common-linux

@@ -48,6 +48,7 @@ hw_cv_func_vsnprintf_c99=${hw_cv_func_vsnprintf_c99=yes}
 
 # coreutils
 gl_cv_func_fstatat_zero_flag=${gl_cv_func_fstatat_zero_flag=yes}
+gl_cv_have_proc_uptime=${gl_cv_have_proc_uptime=yes}
 
 # mysql
 ac_cv_sys_restartable_syscalls=${ac_cv_sys_restartable_syscalls=yes}