package/efl: bump to version 1.21.1

package/efl: bump to version 1.21.1

Remove the --enable-i-really-know-what-i-am-doing[...] option removed by
upstream [1]. But keep BR2_PACKAGE_EFL_HAS_RECOMMENDED_CONFIG at Kconfig
level for Buildroot users since "warnings for disabling features have
been left intact".

Update license file hash since dates was removed from the license text.

[1] https://git.enlightenment.org/core/efl.git/commit/?id=1cda9fe749636484b1328e694a8dbbe4f9d0c31d

Signed-off-by: Romain Naour <romain.naour@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>