Kernel updated to Linux v5.7

[Joel Stanley]

The openbmc kernel has moved to a Linux v5.7 based tree for Aspeed machines.

Quoting the commit message:

 This updates the OpenBMC kernel tree to a 5.7 base. It has been three releases
 since the kernel was updated, making it over 9 months of development time. The
 stable releses up to v5.7.9 are integrated in this bump.

 There are 106 out of tree kernel patches carried in the OpenBMC tree.

Nuvoton is lagging as no one has reviewed the commit:

 https://gerrit.openbmc-project.xyz/c/openbmc/meta-nuvoton/+/34465

Please base future patches on the dev-5.7 tree.

Cheers,

Joel