arch/arm/cpu/arm926ejs/spear/cpu.c: guard do_switch_ecc() with CONFIG_NAND_FSMC

do_switch_ecc() calls fsmc_nand_switch_ecc(), which is a direct
function call into drivers/mtd/nand/fsmc_nand.c. However, this
function is not guarded by CONFIG_NAND_FSMC, which results to a build
failure if CONFIG_NAND_FSMC is disabled.
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>

arch/arm/cpu/arm926ejs/spear/cpu.c

@@ -84,7 +84,7 @@ int print_cpuinfo(void)
 }
 #endif
 
-#if !defined(CONFIG_SPL_BUILD) && defined(CONFIG_NAND_ECC_BCH)
+#if !defined(CONFIG_SPL_BUILD) && defined(CONFIG_NAND_ECC_BCH) && defined(CONFIG_NAND_FSMC)
 static int do_switch_ecc(cmd_tbl_t *cmdtp, int flag, int argc,
 			 char *const argv[])
 {