cassini-[bsp,config]: Remove kas patches from meta-cassini-bsp

meta-cassini-bsp is about to be separated from meta-cassini.

However meta-cassini-bsp contains out-of-tree patches which kas applies
when fetching upstream layers from other repositories. When
meta-cassini-bsp is removed, these patches will not be found.

Before removing meta-cassini-bsp, move the out-of-layer patches to
meta-cassini-config/kas

BSP-specific out-of-layer patches should be avoided as much as possible
going forwards.

Signed-off-by: Adam Johnston <adam.johnston@arm.com>