modules/bash: Disable readline, enable -Os

Disable readline features for interactive shell.  This significantly
reduces the size of bash and doesn't affect scripting features.  The
interactive shell still functions, but there is no history or command
line editing (backspace works, but arrows do not move cursor).

Enable -Os on bash for more size reduction.

This saves about 180KiB from the compressed initrd for
qemu-coreboot-fbwhiptail-tpm2-hotp, almost half the cost of adding
bash.

Signed-off-by: Jonathon Hall <jonathon.hall@puri.sm>

modules/bash

@@ -7,7 +7,7 @@ bash_tar := bash-$(bash_version).tar.gz
 bash_url := https://ftpmirror.gnu.org/bash/$(bash_tar)
 bash_hash := 5bac17218d3911834520dad13cd1f85ab944e1c09ae1aba55906be1f8192f558
 
-bash_configure := ./configure \
+bash_configure := CFLAGS=-Os ./configure \
 	$(CROSS_TOOLS) \
 	--host $(target) \
 	--prefix="/usr" \
@@ -20,6 +20,7 @@ bash_configure := ./configure \
 	--disable-net-redirections \
 	--enable-single-help-strings \
 	--disable-nls \
+	--disable-readline \
 
 bash_target := $(MAKE_JOBS) \
 	&& $(MAKE) -C $(build)/$(bash_dir) \