add back minimal support libraries

some of the libraries removed in [1] were essential to building
anything on efm32 (especially, irq.h).

[1] 4a6f4c0f7d

include/libopencm3/efm32/tinygecko/irq.h

@@ -0,0 +1,55 @@
+/*
+ * This file is part of the libopencm3 project.
+ *
+ * Copyright (C) 2012 chrysn <chrysn@fsfe.org>
+ *
+ * This library is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/** @file
+ *
+ * Definitions of interrupt names on EFM32 Tiny Gecko systems
+ *
+ * The names and numbers are taken from d0034_efm32tg_reference_manual.pdf table 4.1.
+ */
+
+#ifndef LIBOPENCM3_EFM32_TINYGECKO_VECTOR_H
+#define LIBOPENCM3_EFM32_TINYGECKO_VECTOR_H
+
+#define	IRQ_DMA		0
+#define	IRQ_GPIO_EVEN	1
+#define	IRQ_TIMER0	2
+#define	IRQ_USART0_RX	3
+#define	IRQ_USART0_TX	4
+#define	IRQ_ACMP01	5
+#define	IRQ_ADC0	6
+#define	IRQ_DAC0	7
+#define	IRQ_I2C0	8
+#define	IRQ_GPIO_ODD	9
+#define	IRQ_TIMER1	10
+#define	IRQ_USART1_RX	11
+#define	IRQ_USART1_TX	12
+#define	IRQ_LESENSE	13
+#define	IRQ_LEUART0	14
+#define	IRQ_LETIMER0	15
+#define	IRQ_PCNT0	16
+#define	IRQ_RTC		17
+#define	IRQ_CMU		18
+#define	IRQ_VCMP	19
+#define	IRQ_LCD		20
+#define	IRQ_MSC		21
+#define	IRQ_AES		22
+#define	IRQ_COUNT	23 /**< See also d0002_efm32_cortex-m3_reference_manual.pdf's table 1.1's "number of interrupts" line, which shows that there are really no more interrupts and it is sufficient to allocate only 23 slots. */
+
+#endif

lib/efm32/tinygecko/Makefile

@@ -30,7 +30,7 @@ CFLAGS		= -Os -g -Wall -Wextra -I../../../include -fno-common \
 		  -ffunction-sections -fdata-sections -MD -D$(FAMILY)
 # ARFLAGS	= rcsv
 ARFLAGS		= rcs
-OBJS		= vector.o devicerevision.o gpio.o
+OBJS		= vector.o
 
 VPATH += ../