gcc: update gcc7

target/config/Config.in.compiler

@@ -54,7 +54,7 @@ config ADK_TOOLCHAIN_GCC_8
 	depends on !ADK_TARGET_ARCH_OR1K
 
 config ADK_TOOLCHAIN_GCC_7
-	bool "7.3.0"
+	bool "7.4.0"
 	depends on !ADK_TARGET_ARCH_ARC
 	depends on !ADK_TARGET_ARCH_AVR32
 	depends on !ADK_TARGET_ARCH_CSKY

toolchain/gcc/Makefile.inc

@@ -11,8 +11,8 @@ DISTFILES:=		${PKG_NAME}-${PKG_VERSION}.tar.xz
 LIBSTDCXXVER:=		24
 endif
 ifeq ($(ADK_TOOLCHAIN_GCC_7),y)
-PKG_VERSION:=		7.3.0
-PKG_HASH:=		832ca6ae04636adbb430e865a1451adf6979ab44ca1c8374f61fba65645ce15c
+PKG_VERSION:=		7.4.0
+PKG_HASH:=		eddde28d04f334aec1604456e536416549e9b1aa137fc69204e65eb0c009fe51
 PKG_SITES:=		${MASTER_SITE_GNU:=gcc/gcc-${PKG_VERSION}/}
 PKG_RELEASE:=		1
 DISTFILES:=		${PKG_NAME}-${PKG_VERSION}.tar.xz