clang: Allow initializer overrides

In the code we do the following in a number of places
to pre-initialize an array with a certain value before
overwriting some of the array with other values:

 u8 mainboard_picr_data[FCH_INT_TABLE_SIZE] = {
    [0 ... FCH_INT_TABLE_SIZE-1] = 0x1F,
 }

clang does not like that behavior unless we specify
the option -Wno-initializer-overrides.

Remove the check for gcc in those places, too, because
 1) it would silently change array contents between compilers
 2) the check isn't sufficient to determine compilation on
    clang vs gcc

Signed-off-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Change-Id: I93cc121b6fec099fcdbd5fd1114c2ff7cbc291dc
Reviewed-on: https://review.coreboot.org/20384
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
diff --git a/src/mainboard/amd/db-ft3b-lc/mainboard.c b/src/mainboard/amd/db-ft3b-lc/mainboard.c
index 419a57d..a99d15c 100644
--- a/src/mainboard/amd/db-ft3b-lc/mainboard.c
+++ b/src/mainboard/amd/db-ft3b-lc/mainboard.c
@@ -43,9 +43,7 @@
  * MP Tables.  TODO: Make ACPI use these values too.
  */
 static const u8 mainboard_picr_data[FCH_INT_TABLE_SIZE] = {
-#if defined(__GNUC__)
 	[0 ... FCH_INT_TABLE_SIZE-1] = 0x1F,
-#endif
 	/* INTA# - INTH# */
 	[0x00] = 0x0A,0x0B,0x0A,0x0B,0x0A,0x0B,0x0A,0x0B,
 	/* Misc-nil,0,1,2, INT from Serial irq */
@@ -61,9 +59,7 @@
 };
 
 static const u8 mainboard_intr_data[FCH_INT_TABLE_SIZE] = {
-#if defined(__GNUC__)
 	[0 ... FCH_INT_TABLE_SIZE-1] = 0x1F,
-#endif
 	/* INTA# - INTH# */
 	[0x00] = 0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17,
 	/* Misc-nil,0,1,2, INT from Serial irq */
diff --git a/src/mainboard/pcengines/apu2/mainboard.c b/src/mainboard/pcengines/apu2/mainboard.c
index 043bc17..c1ea016 100644
--- a/src/mainboard/pcengines/apu2/mainboard.c
+++ b/src/mainboard/pcengines/apu2/mainboard.c
@@ -50,9 +50,7 @@
  * MP Tables.  TODO: Make ACPI use these values too.
  */
 static const u8 mainboard_picr_data[FCH_INT_TABLE_SIZE] = {
-#if defined(__GNUC__)
 	[0 ... FCH_INT_TABLE_SIZE-1] = 0x1F,
-#endif
 	/* INTA# - INTH# */
 	[0x00] = 0x03,0x03,0x05,0x07,0x0B,0x0A,0x1F,0x1F,
 	/* Misc-nil,0,1,2, INT from Serial irq */
@@ -75,9 +73,7 @@
 };
 
 static const u8 mainboard_intr_data[FCH_INT_TABLE_SIZE] = {
-#if defined(__GNUC__)
 	[0 ... FCH_INT_TABLE_SIZE-1] = 0x1F,
-#endif
 	/* INTA# - INTH# */
 	[0x00] = 0x10,0x10,0x12,0x13,0x14,0x15,0x1F,0x1F,
 	/* Misc-nil,0,1,2, INT from Serial irq */
diff --git a/util/xcompile/xcompile b/util/xcompile/xcompile
index 66073fe..3918346 100755
--- a/util/xcompile/xcompile
+++ b/util/xcompile/xcompile
@@ -254,7 +254,8 @@
 CLANG_CFLAGS_${TARCH}:=${CFLAGS_CLANG}
 CLANG_CFLAGS_${TARCH}+=-no-integrated-as -Qunused-arguments -m${TWIDTH}
 # tone down clang compiler warnings
-CLANG_CFLAGS_${TARCH}+=-Wno-unused-variable -Wno-unused-function -Wno-tautological-compare -Wno-shift-overflow -Wno-address-of-packed-member
+CLANG_CFLAGS_${TARCH}+=-Wno-unused-variable -Wno-unused-function -Wno-tautological-compare
+CLANG_CFLAGS_${TARCH}+=-Wno-shift-overflow -Wno-address-of-packed-member -Wno-initializer-overrides
 CLANG_COMPILER_RT_${TARCH}:=${CC_RT_CLANG}
 CLANG_COMPILER_RT_FLAGS_${TARCH}:=${CC_RT_EXTRA_CLANG}