spl: Kconfig: Replace CONFIG_SPL_FAT_SUPPORT with CONFIG_SPL_FS_FAT

Replace CONFIG_SPL_FAT_SUPPORT with CONFIG_SPL_FS_FAT so
obj-$(CONFIG_$(SPL_)FS_FAT) can be used to control the build in both
SPL and U-Boot.

Signed-off-by: Tien Fong Chee <tien.fong.chee@intel.com>
Reviewed-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/arch/arm/mach-zynqmp/Kconfig b/arch/arm/mach-zynqmp/Kconfig
index 8a311e1..e9f7e7e 100644
--- a/arch/arm/mach-zynqmp/Kconfig
+++ b/arch/arm/mach-zynqmp/Kconfig
@@ -1,6 +1,6 @@
 if ARCH_ZYNQMP
 
-config SPL_FAT_SUPPORT
+config SPL_FS_FAT
 	default y
 
 config SPL_LIBCOMMON_SUPPORT