cosmetic: reset: ast2500: Rename driver and configs

1. Rename AST2500 reset driver from ast2500-reset.c
   to reset-ast2500.c
2. Rename AST2500 reset kconfig option from AST2500_RESET
   to RESET_AST2500

Signed-off-by: Chia-Wei, Wang <chiawei_wang@aspeedtech.com>
Reviewed-by: Ryan Chen <ryan_chen@aspeedtech.com>
diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
index 8b243fd..33c2736 100644
--- a/drivers/reset/Kconfig
+++ b/drivers/reset/Kconfig
@@ -72,7 +72,7 @@
 	  Say Y if you want to control reset signals provided by System Control
 	  block, Media I/O block, Peripheral Block.
 
-config AST2500_RESET
+config RESET_AST2500
 	bool "Reset controller driver for AST2500 SoCs"
 	depends on DM_RESET
 	default y if ASPEED_AST2500