cosmetic: fsl_pmic: cosmetic for the help message

This is cosmetic patch for the help message:

Before:
pmic dump [numregs] dump registers
After:
pmic dump [numregs] - dump registers

Signed-off-by: Jason Liu <jason.hui@linaro.org>
Acked-by: Stefano Babic <sbabic@denx.de>

drivers/misc/fsl_pmic.c

@@ -230,6 +230,6 @@ int do_pmic(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 U_BOOT_CMD(
 	pmic,	CONFIG_SYS_MAXARGS, 1, do_pmic,
 	"Freescale PMIC (Atlas)",
-	"dump [numregs] dump registers\n"
+	"dump [numregs] - dump registers\n"
 	"pmic write <reg> <value> - write register"
 );