efl: Fixed unwanted configure.ac warning.

efl: Fixed unwanted configure.ac warning.

Summary:
Below was the warning:
configure.ac:247: warning: The 'AM_PROG_MKDIR_P' macro is deprecated, and its use is discouraged.
configure.ac:247: You should use the Autoconf-provided 'AC_PROG_MKDIR_P' macro instead,
configure.ac:247: and use '$(MKDIR_P)' instead of '$(mkdir_p)'in your Makefile.am files.

@fix

Signed-off-by: Srivardhan Hebbar <sri.hebbar@samsung.com>
Reviewers: devilhorns

Subscribers: cedric

Differential Revision: https://phab.enlightenment.org/D1341