[U-Boot] RFC: Alternative boot_jump_linux() function

Hi. I'm currently working on snapdragon bootloader support and in the particular case where U-boot is running in Aarch32 and the kernel is Aarch64 the specific implementation is to jump to Linux through SCM call.

I try to find the best possible way to provide an alternative boot function. Adding #ifdef ARCH_SNAPDRAGON will just be too specific in arm/lib/bootm.c in my opinion and I'm thinking of introducing kind of a callback function in gd. that if exists will jump there instead of executing boot_jump_linux().

What do you think ?

Waiting for your thoughts on the subject.

Warm regards, Ramon.