libc: drop NO_FP_LIBC support

NO_FP_LIBC was added in 2004 to save space by disabling FP support in
*printf()/*scanf(). The size benefit is negligible on modern systems
and conflicts with assumptions made by current base utilities.

Remove the option and always build libc with floating-point support.

Reported by:	Oskar Holmlund <eovholmlund at gmail com>
MFC after:	2 weeks

share/man/man5/src.conf.5

@@ -1,5 +1,5 @@
 .\" DO NOT EDIT-- this file is @generated by tools/build/options/makeman.
-.Dd January 12, 2026
+.Dd January 16, 2026
 .Dt SRC.CONF 5
 .Os
 .Sh NAME
@@ -761,10 +761,6 @@ when compiling the kernel.
 Also disables all format checking.
 .It Va WITHOUT_FORTH
 Build bootloaders without Forth support.
-.It Va WITHOUT_FP_LIBC
-Build
-.Nm libc
-without floating-point support.
 .It Va WITHOUT_FREEBSD_UPDATE
 Do not build
 .Xr freebsd-update 8 .

share/mk/src.opts.mk

@@ -99,7 +99,6 @@ __DEFAULT_YES_OPTIONS = \
     FINGER \
     FLOPPY \
     FORTH \
-    FP_LIBC \
     FREEBSD_UPDATE \
     FTP \
     GAMES \