x11/qt5/qtbase fix build on sparc64

qt5/base build failure blocks 677 ports from building on sparc64. It fails
in configure with:

ERROR: Feature 'icu' was enabled, but the pre-condition 'libs.icu' failed.

This is because the configure stage check for icu requiers c++17 but did
not specifiy it. With the attached diff sparc64 builds and packages ok.
I also tested amd64 also builds find with this patch.

okay?

Index: Makefile
===================================================================
RCS file: /cvs/ports/x11/qt5/qtbase/Makefile,v
retrieving revision 1.77
diff -u -p -u -r1.77 Makefile
--- Makefile 1 Dec 2024 14:51:17 -0000 1.77
+++ Makefile 13 Dec 2024 22:57:42 -0000
@@ -3,6 +3,8 @@ QT5NAME = QtBase
KDE_COMMIT = 2529f7f0c2333d437089c775c9c30f624d1fd5bc
KDE_VERSION = 130

+REVISION = 0
+
COMMENT-main = C++ general-purpose toolkit
COMMENT-global = global Qt5 documentation internals
COMMENT-mysql = MySQL plugin for Qt5
Index: patches/patch-src_corelib_configure_json
===================================================================
RCS file: patches/patch-src_corelib_configure_json
diff -N patches/patch-src_corelib_configure_json
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ patches/patch-src_corelib_configure_json 13 Dec 2024 22:57:42 -0000
@@ -0,0 +1,15 @@
+icu needs c++17
+
+Index: src/corelib/configure.json
+--- src/corelib/configure.json.orig
++++ src/corelib/configure.json
+@@ -102,7 +102,8 @@
+ "UCollator *collator = ucol_open(\"ru_RU\", &status);",
+ "if (!U_FAILURE(status))",
+ " ucol_close(collator);"
+- ]
++ ],
++ "qmake": "CONFIG += c++17"
+ },
+ "headers": [ "unicode/utypes.h", "unicode/ucol.h", "unicode/ustring.h" ],
+ "sources": [