stm32g0: add crc.

Regular crc-v2 peripheral, except that CRC_IDR is now 32bit wide - but
not used.

include/libopencm3/stm32/crc.h

@@ -36,6 +36,8 @@
 #       include <libopencm3/stm32/l1/crc.h>
 #elif defined(STM32L4)
 #       include <libopencm3/stm32/l4/crc.h>
+#elif defined(STM32G0)
+#       include <libopencm3/stm32/g0/crc.h>
 #else
 #       error "stm32 family not defined."
 #endif

include/libopencm3/stm32/g0/crc.h

@@ -0,0 +1,31 @@
+/** @defgroup crc_defines CRC Defines
+ *
+ * @brief <b>Defined Constants and Types for the STM32G0xx CRC Generator </b>
+ *
+ * @ingroup STM32G0xx_defines
+ *
+ * LGPL License Terms @ref lgpl_license
+ */
+/*
+ * This file is part of the libopencm3 project.
+ *
+ * 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/>.
+ */
+
+#ifndef LIBOPENCM3_CRC_H
+#define LIBOPENCM3_CRC_H
+
+#include <libopencm3/stm32/common/crc_v2.h>
+
+#endif

lib/stm32/g0/Makefile

@@ -44,6 +44,7 @@ OBJS += usart_common_all.o usart_common_v2.o
 OBJS += spi_common_all.o spi_common_v1_frf.o
 OBJS += i2c_common_v2.o
 OBJS += rng_common_v1.o
+OBJS += crc_common_all.o
 
 VPATH +=../:../../cm3:../common