remove IAR toolchain support from make build system

IAR is only supported with CMake. Remove all IAR-specific references
from the Make build system including toolchain files, SRC_S_IAR,
LD_FILE_IAR variables, and IAR toolchain detection.

Also fix GET_SECTOR_COUNT truncation in msc_file_explorer and
broken formatting in stm32f7 board_uart_write.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: hathach

examples/build_system/make/cpu/arm1176jzf-s.mk

@@ -2,8 +2,4 @@ ifeq ($(TOOLCHAIN),gcc)
   CFLAGS += \
     -mcpu=arm1176jzf-s \
 
-else ifeq ($(TOOLCHAIN),iar)
-	#CFLAGS += --cpu cortex-a53
-	#ASFLAGS += --cpu cortex-a53
-
 endif

examples/build_system/make/cpu/arm926ej-s.mk

@@ -2,8 +2,4 @@ ifeq ($(TOOLCHAIN),gcc)
   CFLAGS += \
     -mcpu=arm926ej-s \
 
-else ifeq ($(TOOLCHAIN),iar)
-	#CFLAGS += --cpu cortex-a53
-	#ASFLAGS += --cpu cortex-a53
-
 endif

examples/build_system/make/cpu/cortex-a53.mk

@@ -2,10 +2,6 @@ ifeq ($(TOOLCHAIN),gcc)
   CFLAGS += \
     -mcpu=cortex-a53 \
 
-else ifeq ($(TOOLCHAIN),iar)
-	CFLAGS += \
-		--cpu cortex-a53 \
-
 	ASFLAGS += \
 		--cpu cortex-a53 \
 

examples/build_system/make/cpu/cortex-a72.mk

@@ -2,10 +2,6 @@ ifeq ($(TOOLCHAIN),gcc)
   CFLAGS += \
     -mcpu=cortex-a72 \
 
-else ifeq ($(TOOLCHAIN),iar)
-	CFLAGS += \
-		--cpu cortex-a72 \
-
 	ASFLAGS += \
 		--cpu cortex-a72 \
 

examples/build_system/make/cpu/cortex-m0.mk

@@ -9,11 +9,6 @@ else ifeq ($(TOOLCHAIN),clang)
 	  --target=arm-none-eabi \
 	  -mcpu=cortex-m0 \
 
-else ifeq ($(TOOLCHAIN),iar)
-  # IAR Flags
-  CFLAGS += --cpu cortex-m0
-  ASFLAGS += --cpu cortex-m0
-
 else
   $(error "TOOLCHAIN is not supported")
 endif

examples/build_system/make/cpu/cortex-m0plus.mk

@@ -9,11 +9,6 @@ else ifeq ($(TOOLCHAIN),clang)
 	  --target=arm-none-eabi \
 	  -mcpu=cortex-m0plus \
 
-else ifeq ($(TOOLCHAIN),iar)
-  # IAR Flags
-  CFLAGS += --cpu cortex-m0+
-  ASFLAGS += --cpu cortex-m0+
-
 else
   $(error "TOOLCHAIN is not supported")
 endif

examples/build_system/make/cpu/cortex-m23.mk

@@ -9,11 +9,6 @@ else ifeq ($(TOOLCHAIN),clang)
 	  --target=arm-none-eabi \
 	  -mcpu=cortex-m23 \
 
-else ifeq ($(TOOLCHAIN),iar)
-  # IAR Flags
-  CFLAGS += --cpu cortex-m23
-  ASFLAGS += --cpu cortex-m23
-
 else
   $(error "TOOLCHAIN is not supported")
 endif

examples/build_system/make/cpu/cortex-m3.mk

@@ -9,11 +9,6 @@ else ifeq ($(TOOLCHAIN),clang)
 	  --target=arm-none-eabi \
 	  -mcpu=cortex-m3 \
 
-else ifeq ($(TOOLCHAIN),iar)
-  # IAR Flags
-  CFLAGS += --cpu cortex-m3
-  ASFLAGS += --cpu cortex-m3
-
 else
   $(error "TOOLCHAIN is not supported")
 endif

examples/build_system/make/cpu/cortex-m33-nodsp-nofp.mk

@@ -10,10 +10,6 @@ else ifeq ($(TOOLCHAIN),clang)
 	  -mcpu=cortex-m33 \
 	  -mfpu=softvp \
 
-else ifeq ($(TOOLCHAIN),iar)
-  CFLAGS += \
-		--cpu cortex-m33+nodsp \
-
   ASFLAGS += \
 		--cpu cortex-m33+nodsp \
 

examples/build_system/make/cpu/cortex-m33.mk

@@ -11,11 +11,6 @@ else ifeq ($(TOOLCHAIN),clang)
 	  -mcpu=cortex-m33 \
 	  -mfpu=fpv5-sp-d16 \
 
-else ifeq ($(TOOLCHAIN),iar)
-  CFLAGS += \
-		--cpu cortex-m33 \
-		--fpu VFPv5-SP \
-
   ASFLAGS += \
 		--cpu cortex-m33 \
 		--fpu VFPv5-SP \