Makefile.in: guarantee directory creation at install time before file…

[trofi]

… copy

With help of 'make --shuffle' mode (https://savannah.gnu.org/bugs/index.php?62100)
I found a few missing target dependencies in 'make install' of gpm.

One of the failures is a reference to missing directory:

$ make install --shuffle
make -C src dep
make[1]: Entering directory '/build/gpm/src'
# make links in srcdir
make[1]: [Makefile:92: dep] Error 1 (ignored) shuffle=1655759403
# create dependencies
for DEPS in `echo *.c */*.c`; do \
gcc -I. -I /build/gpm/src -I /build/gpm/src/headers -M  -I/build/gpm/src -DHAVE_CONFIG_H -include headers/config.h -Wall -DSYSCONFDIR="\"/etc\"" -DSBINDIR="\"../gpm-unstable-2020-06-17/sbin\"" -D_GNU_SOURCE  $DEPS | \
sed 's/^\(.*\)\.o\([ :]+\)/\1.o \1.lo\2/g' >> .depend ; done
make[1]: Leaving directory '/build/gpm/src'
make[1]: Entering directory '/build/gpm/src'
make[1]: Nothing to be done for 'all'.
make[1]: Leaving directory '/build/gpm/src'
make[1]: Entering directory '/build/gpm/doc'
make[1]: Nothing to be done for 'all'.
make[1]: Leaving directory '/build/gpm/doc'
make[1]: Entering directory '/build/gpm/contrib'
make[1]: Nothing to be done for 'all'.
make[1]: Leaving directory '/build/gpm/contrib'
make[1]: Entering directory '/build/gpm/src'
install -c gpm ../gpm-unstable-2020-06-17/sbin/gpm
install: cannot create regular file '../gpm-unstable-2020-06-17/sbin/gpm': No such file or directory

Note that in this case 'gmp' binary installation attempts to copy
the binary before target directory is created. The change adds a depend.