tools/testing/cxl: Remove unused SZ_512G macro

SZ_512G macro has become useless since commit b2f3b74e1072
("tools/testing/cxl: Move cxl_test resources to the top of memory")
so remove it directly.

Signed-off-by: Xiao Yang <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Reviewed-by: Dave Jiang <[e-mail]>
Signed-off-by: Vishal Verma <[e-mail]>

tools/testing/cxl/test/cxl.c

···
 #define SZ_64G (SZ_32G * 2)
 #endif
 
-#ifndef SZ_512G
-#define SZ_512G (SZ_64G * 8)
-#endif
-
 static __init int cxl_rch_init(void)
 {
 	int rc, i;