powerpc: Drop default CONFIG_MAX_CPUS

This configuration has been moved into Kconfig for mpc85xx, and
dropped for mpc86xx. Remove the default value in config.h.

Signed-off-by: York Sun <york.sun@nxp.com>

arch/powerpc/include/asm/config.h

@@ -57,10 +57,6 @@
 #endif
 #endif
 
-#ifndef CONFIG_MAX_CPUS
-#define CONFIG_MAX_CPUS		1
-#endif
-
 /*
  * Provide a default boot page translation virtual address that lines up with
  * Freescale's default e500 reset page.