3rdparty/intel-microcode: Update submodule to 20210608 release

Update submodule pointer to include microcode for TGL and others.

Tested the following still boot:

- galp3-c (WHL-U): sig=0x806eb pf=0x80 revision=0xe9
- oryp5 (CFL-H): sig=0x906ea pf=0x20 revision=0xe9
- gaze15 (CML-H): sig=0xa0652 pf=0x20 revision=0xe9

coreboot reports the revision as -1 from what it actually is. i.e.,
these should report revision=0xea (and that is what Linux reports).
However, this behavior is not new.

Change-Id: I084ba67e8eaf7383f1c05fa5589b63c92ff900b1
Signed-off-by: Tim Crawford <tcrawford@system76.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/56861
Reviewed-by:  Felix Singer <felixsinger@posteo.net>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

3rdparty/intel-microcode

@@ -1 +1 @@
-Subproject commit 49bb67f32a2e3e631ba1a9a73da1c52e1cac7fd9
+Subproject commit 3f97690f0da8011f52209b232450a1e5c4f2e1f6