net: i825xx: Use absolute_pointer for memcpy from fixed memory location
gcc 11.x reports the following compiler warning/error.
drivers/net/ethernet/i825xx/82596.c: In function 'i82596_probe':
arch/m68k/include/asm/string.h:72:25: error:
'__builtin_memcpy' reading 6 bytes from a region of size 0 [-Werror=stringop-overread]
Use absolute_pointer() to work around the problem.