Drop CONFIG_MAX_PHYSICAL_CPUS on non-AMD boards

CONFIG_MAX_PHYSICAL_CPUS is defined by quite a number of
mainboards whithout any code actually using the variable.
Hence, drop MAX_PHYSICAL_CPUS from Kconfig for those boards.

In the long run we should drop CONFIG_MAX_PHYSICAL_CPUS use
completely and make the code dynamic or depend on CONFIG_MAX_CPUS
instead.

Change-Id: I37dcc74d245ddba5186b96bd82220dacb6f4d323
Signed-off-by: Stefan Reinauer <reinauer@google.com>
Reviewed-on: http://review.coreboot.org/984
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>

src/cpu/Kconfig

@@ -19,6 +19,8 @@ config DCACHE_RAM_GLOBAL_VAR_SIZE
 	hex
 	default 0x0
 
+# FIXME MAX_PHYSICAL_CPUS should move to AMD specific code, or better
+# yet be dropped completely.
 config MAX_PHYSICAL_CPUS
 	int
 	default 1