tools/x86/kcpuid: Add missing dir via Makefile

tools/x86/kcpuid: Add missing dir via Makefile

So far the Makefile just installed the csv into $(HWDATADIR)/cpuid.csv, which
made it unaware about $DESTDIR. Add $DESTDIR to the install command and while
at it also create the directory, should it not exist already. This eases the
packaging of kcpuid and allows i.e. for the install on Arch to look like this:

  $ make BINDIR=/usr/bin DESTDIR="$pkgdir" -C tools/arch/x86/kcpuid install

Some background on DESTDIR:

DESTDIR is commonly used in packaging for staged installs (regardless of the
used package manager):

  https://www.gnu.org/prep/standards/html_node/DESTDIR.html

So the package is built and installed into a directory which the package
manager later picks up and creates some archive from it.

What is specific to Arch Linux here is only the usage of $pkgdir in the
example, DESTDIR itself is widely used.

  [ bp: Extend the commit message with Christian's info on DESTDIR as a GNU
    coding standards thing. ]

Signed-off-by: Christian Heusel <christian@heusel.eu>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20240531111757.719528-2-christian@heusel.eu