Introduce intel_bug_present function.

Put the code to check present of the Intel bug from parport_EPP_supported
into new intel_bug_present function. The later also return ECR register
to the state it has before function call.

Signed-off-by: Matwey V. Kornilov <matwey@sai.msu.ru>
Implement CPU model check to cut off false-positives

The code in intel_bug_present is known to produce much false-positives.
It is believed that the affected by the bug hardware are used with either Intel 80486 or Pentium.

Perform the check only when the kernel configured as CONFIG_X86_32,
then use cpuinfo_x86 of the first available CPU to check the model
and run initial check code.

Suggested-by: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
Signed-off-by: Matwey V. Kornilov <matwey@sai.msu.ru>