desolve machine_init.c similar to what we did for machine.c

machine/PCB_SWTG018AS_V2_1_0_init.c

@@ -0,0 +1,18 @@
+#include "machine_init_defs.h"
+
+static __code const struct { uint16_t reg; uint32_t val; } custom_init_regs[] = {
+	{ RTL837X_REG_LED3_0_SET1,   0x00100000UL },
+	{ RTL837X_REG_LED1_0_SET1,   0x01400155UL },
+	{ RTL837X_REG_LED1_0_SET0,   0x01740141UL },
+	{ RTL837X_REG_LED_GLB_IO_EN, 0x7f24977fUL },
+	{ RTL837X_PIN_MUX_0,         0x20db6880UL },
+};
+
+void machine_custom_init(void) __banked
+{
+	uint8_t i;
+	// REG_SET is a multi-statement macro without a do-while wrapper: braces required
+	for (i = 0; i < sizeof(custom_init_regs) / sizeof(custom_init_regs[0]); i++) {
+		REG_SET(custom_init_regs[i].reg, custom_init_regs[i].val);
+	}
+}