Qorvo pac55xx: initial support

Qorvo (Nee Active Semi) PAC55xx "Intelligent Motor Control" parts,
cortex-m4 SoCs

lib/pac55xx/vector_chipset.c

@@ -0,0 +1,25 @@
+/*
+ * This file is part of the libopencm3 project.
+ *
+ * Copyright (C) 2019 Brian Viele <vielster@allocor.tech>
+ *
+ * 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/>.
+ */
+
+/* Standard Cortex-M4F initialization of FPU. */
+static void pre_main(void)
+{
+	/* Enable FPU */
+	SCB_CPACR |= SCB_CPACR_FULL * (SCB_CPACR_CP10 | SCB_CPACR_CP11);
+}