build-sys: rearrange gitignore in alphabetical order

Signed-off-by: Enze Li <lienze@kylinos.cn>

.gitignore

@@ -46,6 +46,10 @@ config/test-driver
 configure
 cscope.out
 depcomp
+GPATH
+GRTAGS
+GTAGS
+GSYMS
 INSTALL
 install-sh
 libtool
@@ -64,16 +68,13 @@ tests/run.sh.log
 tests/run.sh.trs
 update.log
 ylwrap
-GPATH
-GRTAGS
-GTAGS
-GSYMS
 
 #
 # binaries
 #
 /addpart
 /agetty
+/build*/
 /blkdiscard
 /blkid
 /blkpr
@@ -197,4 +198,3 @@ GSYMS
 /wipefs
 /write
 /zramctl
-/build*/