kernel: bump 6.6 to 6.6.97

kernel: bump 6.6 to 6.6.97

Changelog: https://cdn.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.6.97

Remove upstream patch:
  generic/backport-6.6/001-powerpc-kernel-Fix-pcc_save_regs-inclusion.patch[1]

Manually rebased patch:
  bcm53xx/patches-6.6/180-usb-xhci-add-support-for-performing-fake-doorbell.patch[2]

All other patches are automatically refreshed.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=v6.6.97&id=8a7ac2737211451b8b98657b919c4c4e0a4c0c2f
[2] https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=v6.6.97&id=7609899eb6b70b536123eb58eeab27c764752b82

Signed-off-by: Shiji Yang <[email protected]>
Co-authored-by: John Audia <[email protected]>
Tested-by: Konstantin Demin <[email protected]>
Link: https://github.com/openwrt/openwrt/pull/19317
Signed-off-by: Hauke Mehrtens <[email protected]>