build: add efl as internal dep for eldbus

build: add efl as internal dep for eldbus

The build stop wile building eldbus-codegen:

  CCLD     bin/eldbus/eldbus-codegen
  CXXLD    bin/eolian_cxx/eolian_cxx
  CCLD     lib/ecore_x/ecore_x_vsync
  CCLD     lib/evas/common/libevas_op_blend_sse3.la
  CCLD     lib/evas/common/libevas_convert_rgb_32.la
  CCLD     lib/ecore_ipc/libecore_ipc.la
[...]/i686-ctng-linux-gnu/bin/ld: warning: libefl.so.1, needed by lib/ecore/.libs/libecore.so, not found (try using -rpath or -rpath-link)
lib/ecore/.libs/libecore.so: undefined reference to `efl_control_suspend_set'
lib/ecore/.libs/libecore.so: undefined reference to `efl_control_interface_get'
collect2: error: ld returned 1 exit status
Makefile:19135: recipe for target 'bin/eldbus/eldbus-codegen' failed
make[6]: *** [bin/eldbus/eldbus-codegen] Error 1

A dependency on libefl seems to be missing for eldbus.

Fixes T2718 and T2952

Signed-off-by: Romain Naour <romain.naour@openwide.fr>