package/libtomcrypt: compile with -fPIC to enable linking to dynamic libraries/exectu...

package/libtomcrypt: compile with -fPIC to enable linking to dynamic libraries/exectuables

Fixes:

  .../x86_64-buildroot-linux-gnu/bin/ld: .../host/x86_64-buildroot-linux-gnu/sysroot/usr/lib/libtomcrypt.a(md5.o): relocation R_X86_64_32 against `.rodata.str1.1' can not be used when making a shared object; recompile with -fPIC

when building a shared library that links with libtomcrypt. Our only
internal user dropbear doesn't do this, so there are no autobuilder
failures.

Signed-off-by: Peter Seiderer <ps.report@gmx.net>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>