driver: Express build dependency on version.h

This fixes the issue that the driver module is not rebuilt properly when
the version header changes.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
x86: Fix assembly constraints in per_cpu()

lea's second operand can only be a register. Adjust the constraints
accordingly. LLVM/clang stumbled over this.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
inmates: x86: Use .code16 instead of .code16gcc

This removes support for binutils < 2.16 but makes us more portable.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
inmates: x86: Refactor lgdt instruction expression

This expresses the intention to load from gdt_ptr using CS clearer than
via the cs prefix, and it is more portable to other assemblers (namely
that of clang).

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>