ntpd: drop unneeded uClibc workaround for refclock_pcf.c

refclock_pcf.c contains code using the tm_gmtoff member of struct tm, which
is only available on uClibc if it is built with __UCLIBC_HAS_TM_EXTENSIONS__.

This change date back to:

commit 7129da009cc72575a84a30c4587bd99f745c49d4
Author: Eric Andersen <andersen@codepoet.org>
Date:   Sat Jan 18 21:27:22 2003 +0000

    Merge a bunch of stuff over from the tuxscreen buildroot, with
    many updates to make things be more consistant.
     -Erik

But nowadays our uClibc configs DO enable __UCLIBC_HAS_TM_EXTENSIONS__, so
it is no longer needed and can be dropped.

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/ntp/ntp.mk

@@ -40,10 +40,6 @@ else
 NTP_CONF_OPTS += --disable-ATOM
 endif
 
-define NTP_PATCH_FIXUPS
-	$(SED) "s,^#if.*__GLIBC__.*_BSD_SOURCE.*$$,#if 0," $(@D)/ntpd/refclock_pcf.c
-endef
-
 NTP_INSTALL_FILES_$(BR2_PACKAGE_NTP_NTP_KEYGEN) += util/ntp-keygen
 NTP_INSTALL_FILES_$(BR2_PACKAGE_NTP_NTP_WAIT) += scripts/ntp-wait/ntp-wait
 NTP_INSTALL_FILES_$(BR2_PACKAGE_NTP_NTPDATE) += ntpdate/ntpdate