x86/microcode/intel: Rename get_datasize() since its used externally

Rename get_datasize() to intel_microcode_get_datasize() and make it an inline.

  [ tglx: Make the argument typed and fix up the IFS code ]

Suggested-by: Boris Petkov <bp@alien8.de>
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20230812195727.894165745@linutronix.de