lx_emul: update default linux port to version 6.6.x

[ssumpf]

Our yearly update of dde_linux.

Steps:

• move the old linux.port to legacy_linux.port and update all dependencies
• create new linux.port using a 6.6 kernel
• adjust virt_linux
• adjust pc_linux
• adjust a64_linux
• adjust rpi_linux
• adjust imx_linux
• adjust zynq_linux

Known changes:

• kernel_thread takes new char const *name as third argument
• _Generic requires exact return values, for example struct page *pmd_page(pmd_t pmd) cannot be #define pmd_page NULL

[ssumpf]

These commits mark the first three steps. This is a starting point and more testing on all platforms is still required.