Revert "Makefile: Build with -Werror=date-time if the compiler supports it"

Revert "Makefile: Build with -Werror=date-time if the compiler supports it"

This reverts commit fe7c36c7bde1
("Makefile: Build with -Werror=date-time if the compiler supports it")

Revert this change because UEK 4.1 still uses __DATE__ and __TIME__ macro
and building UEK with GCC 4.9 or newer should not cause compilation errors.

Orabug: 27132235

Signed-off-by: Gayatri Vasudevan <gayatri.vasudevan@oracle.com>
Reviewed-by: John Haxby <john.haxby@oracle.com>
Acked-by: HÃ¥kon Bugge <haakon.bugge@oracle.com>
Acked-by: Girish Moodalbail <girish.moodalbail@oracle.com>