arm: Tegra2: Fix ELDK42 gcc failure with inline asm stack pointer load

The 4.2.2 gcc in the ELDK42 release doesn't like the direct SP
load using a constant in tegra2_start. Change it to use a load
thru another reg using mov sp, %0 : : "r"(CONST).

Tested on my Seaboard T20-A03, U-Boot loads and runs OK. Also
compiled all tegra2 builds with both gcc 4.2.2 and 4.4.1 OK.

Signed-off-by: Tom Warren <twarren@nvidia.com>
Acked-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>

arch/arm/cpu/armv7/tegra2/ap20.c

@@ -298,11 +298,11 @@ void tegra2_start(void)
 		writel(0xC0, &pmt->pmt_cfg_ctl);
 
 		/*
-		* If we are ARM7 - give it a different stack. We are about to
-		* start up the A9 which will want to use this one.
-		*/
-		asm volatile("ldr	sp, =%c0\n"
-			: : "i"(AVP_EARLY_BOOT_STACK_LIMIT));
+		 * If we are ARM7 - give it a different stack. We are about to
+		 * start up the A9 which will want to use this one.
+		 */
+		asm volatile("mov	sp, %0\n"
+			: : "r"(AVP_EARLY_BOOT_STACK_LIMIT));
 
 		start_cpu((u32)_start);
 		halt_avp();