Remove unused variables from gdbserver's Makefile

This removes a number of unused variables from gdbserver's Makefile.
I found these while working on the subsequent patches, and figured it
would be cleaner to have a separate patch for the deletions.

gdbserver/Makefile.in

@@ -26,23 +26,7 @@ target_alias = @target_noncanonical@
 program_transform_name = @program_transform_name@
 bindir = @bindir@
 libdir = @libdir@
-tooldir = $(libdir)/$(target_alias)
 
-datarootdir = @datarootdir@
-datadir = @datadir@
-mandir = @mandir@
-man1dir = $(mandir)/man1
-man2dir = $(mandir)/man2
-man3dir = $(mandir)/man3
-man4dir = $(mandir)/man4
-man5dir = $(mandir)/man5
-man6dir = $(mandir)/man6
-man7dir = $(mandir)/man7
-man8dir = $(mandir)/man8
-man9dir = $(mandir)/man9
-infodir = @infodir@
-htmldir = $(prefix)/html
-includedir = @includedir@
 CONFIG_SRC_SUBDIR = @CONFIG_SRC_SUBDIR@
 
 install_sh = @install_sh@
@@ -290,16 +274,7 @@ extra_libraries = @extra_libraries@
 FLAGS_TO_PASS = \
 	"prefix=$(prefix)" \
 	"exec_prefix=$(exec_prefix)" \
-	"infodir=$(infodir)" \
-	"datarootdir=$(datarootdir)" \
-	"docdir=$(docdir)" \
-	"htmldir=$(htmldir)" \
-	"pdfdir=$(pdfdir)" \
 	"libdir=$(libdir)" \
-	"mandir=$(mandir)" \
-	"datadir=$(datadir)" \
-	"includedir=$(includedir)" \
-	"against=$(against)" \
 	"DESTDIR=$(DESTDIR)" \
 	"AR=$(AR)" \
 	"AR_FLAGS=$(AR_FLAGS)" \