libpayload: Move base address, stack and heap size to Kconfig

This will allow more payloads to use the standard linker script
instead of implementing their own.

Change-Id: Ie60120769829f427ceb722109d85859b61dbde31
Signed-off-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Reviewed-on: https://review.coreboot.org/14074
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>

payloads/libpayload/arch/mips/libpayload.ldscript

@@ -20,15 +20,11 @@
 
 OUTPUT_ARCH(mips)
 
-BASE_ADDRESS = 0x00000000;
 ENTRY(_entry)
 
-HEAP_SIZE = 2*64*1024;
-STACK_SIZE = 16*1024;
-
 SECTIONS
 {
-	. = BASE_ADDRESS;
+	. = CONFIG_LP_BASE_ADDRESS;
 
 	. = ALIGN(16);
 	_start = .;
@@ -68,12 +64,12 @@ SECTIONS
 
 		. = ALIGN(16);
 		_heap = .;
-		. += HEAP_SIZE;
+		. += CONFIG_LP_HEAP_SIZE;
 		. = ALIGN(16);
 		_eheap = .;
 
 		_estack = .;
-		. += STACK_SIZE;
+		. += CONFIG_LP_STACK_SIZE;
 		. = ALIGN(16);
 		_stack = .;
 	}