Fix path to GCC linker scripts

The linux filesystem is case sensitive, this was causing our nightly build to
fail when attempting to find the script with its lower case name. The
name of the file has been kept the same as this seems to be STMs
convention.

Author: harrisonmutai-arm

targets/TARGET_STM/TARGET_STM32F0/TARGET_STM32F070xB/CMakeLists.txt

@@ -5,7 +5,7 @@ add_subdirectory(TARGET_NUCLEO_F070RB EXCLUDE_FROM_ALL)
 
 if(${MBED_TOOLCHAIN} STREQUAL "GCC_ARM")
     set(STARTUP_FILE TOOLCHAIN_GCC_ARM/startup_stm32f070xb.S)
-    set(LINKER_FILE TOOLCHAIN_GCC_ARM/stm32f070xb.ld)
+    set(LINKER_FILE TOOLCHAIN_GCC_ARM/STM32F070XB.ld)
 elseif(${MBED_TOOLCHAIN} STREQUAL "ARM")
     set(STARTUP_FILE TOOLCHAIN_ARM/startup_stm32f070xb.S)
     set(LINKER_FILE TOOLCHAIN_ARM/stm32f070xb.sct)

targets/TARGET_STM/TARGET_STM32F0/TARGET_STM32F072xB/CMakeLists.txt

@@ -5,7 +5,7 @@ add_subdirectory(TARGET_NUCLEO_F072RB EXCLUDE_FROM_ALL)
 
 if(${MBED_TOOLCHAIN} STREQUAL "GCC_ARM")
     set(STARTUP_FILE TOOLCHAIN_GCC_ARM/startup_stm32f072xb.S)
-    set(LINKER_FILE TOOLCHAIN_GCC_ARM/stm32f072xb.ld)
+    set(LINKER_FILE TOOLCHAIN_GCC_ARM/STM32F072XB.ld)
 elseif(${MBED_TOOLCHAIN} STREQUAL "ARM")
     set(STARTUP_FILE TOOLCHAIN_ARM/startup_stm32f072xb.S)
     set(LINKER_FILE TOOLCHAIN_ARM/stm32f072xb.sct)

targets/TARGET_STM/TARGET_STM32F0/TARGET_STM32F091xC/CMakeLists.txt

@@ -5,7 +5,7 @@ add_subdirectory(TARGET_NUCLEO_F091RC EXCLUDE_FROM_ALL)
 
 if(${MBED_TOOLCHAIN} STREQUAL "GCC_ARM")
     set(STARTUP_FILE TOOLCHAIN_GCC_ARM/startup_stm32f091xc.S)
-    set(LINKER_FILE TOOLCHAIN_GCC_ARM/stm32f091xc.ld)
+    set(LINKER_FILE TOOLCHAIN_GCC_ARM/STM32F091XC.ld)
 elseif(${MBED_TOOLCHAIN} STREQUAL "ARM")
     set(STARTUP_FILE TOOLCHAIN_ARM/startup_stm32f091xc.S)
     set(LINKER_FILE TOOLCHAIN_ARM/stm32f091xc.sct)