arm: spear: Call the SPL 'SPL', not 'Xloader'

Rename Xloader as SPL in comments.
Signed-off-by: NMiquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: NStefan Roese <sr@denx.de>

arch/arm/cpu/arm926ejs/spear/start.S

@@ -33,14 +33,14 @@
 
 reset:
 /*
- * Xloader has to return back to BootROM in a few cases.
+ * SPL has to return back to BootROM in a few cases.
  * eg. Ethernet boot, UART boot, USB boot
  * Saving registers for returning back
  */
 	stmdb	sp!, {r0-r12,r14}
 	bl	cpu_init_crit
 /*
- * Clearing bss area is not done in Xloader.
+ * Clearing bss area is not done in SPL.
  * BSS area lies in the DDR location which is not yet initialized
  * bss is assumed to be uninitialized.
  */