add linker and startup for lpcxpresso11u68 board

able to build and blink LED

hw/bsp/lpcxpresso11u68/board.mk

@@ -0,0 +1,39 @@
+CFLAGS += \
+  -mthumb \
+  -mabi=aapcs \
+  -mcpu=cortex-m0plus \
+  -nostdlib \
+  -DCORE_M0PLUS \
+  -D__VTOR_PRESENT=0 \
+  -DCFG_TUSB_MCU=OPT_MCU_LPC11UXX \
+  -D__USE_LPCOPEN \
+  '-DCFG_TUSB_MEM_SECTION= __attribute__((section(".data.$RAM3")))' \
+  '-DCFG_TUSB_MEM_ALIGN=__attribute__ ((aligned(64)))' 
+
+# All source paths should be relative to the top level.
+LD_FILE = hw/bsp/lpcxpresso11u68/lpc11u68.ld
+
+SRC_C += \
+	hw/mcu/nxp/lpcopen/lpc_chip_11u6x/src/chip_11u6x.c \
+	hw/mcu/nxp/lpcopen/lpc_chip_11u6x/src/clock_11u6x.c \
+	hw/mcu/nxp/lpcopen/lpc_chip_11u6x/src/gpio_11u6x.c \
+	hw/mcu/nxp/lpcopen/lpc_chip_11u6x/src/iocon_11u6x.c \
+	hw/mcu/nxp/lpcopen/lpc_chip_11u6x/src/syscon_11u6x.c \
+	hw/mcu/nxp/lpcopen/lpc_chip_11u6x/src/sysinit_11u6x.c
+
+INC += \
+	$(TOP)/hw/mcu/nxp/lpcopen/lpc_chip_11u6x/inc
+
+# For TinyUSB port source
+VENDOR = nxp
+CHIP_FAMILY = lpc11_13_15
+
+# For freeRTOS port source
+FREERTOS_PORT = ARM_CM0
+
+# For flash-jlink target
+JLINK_DEVICE = LPC11U68
+JLINK_IF = swd
+
+# flash using jlink
+flash: flash-jlink