package/gdb: gdb+expat build fix
Commit 23413b51b2308225584b65c2fcd800ca8f7c56af added --with-expat
configure option and expat dependency when BR2_PACKAGE_EXPAT is
configured. When cross-compiling, gdb configure fails because the host
system libexpat is referenced.
Configuring gdb with
--with-libexpat-prefix=$(STAGING_DIR)/usr
fixes the reference and allows gdb to build successfully.
Tested with arm-buildroot-linux-gnueabihf toolchain.
Signed-off-by: Doug Kehn <rdkehn@yahoo.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>