soc: xlnx: zynq7000: add FPU support

According to its datasheet the Zynq 7000 has a VFPv3 FPU

Signed-off-by: Simon Maurer <mail@maurer.systems>

arch/arm/core/Kconfig.vfp

@@ -109,6 +109,18 @@ config VFP_U_DP_D16_FP16_FMAC
 	  fused multiply-accumulate) and floating-point exception trapping with 16
 	  double-word registers.
 
+config VFP_DP_D32_FMAC
+	bool
+	select CPU_HAS_VFP
+	select VFP_FEATURE_SINGLE_PRECISION
+	select VFP_FEATURE_DOUBLE_PRECISION
+	select VFP_FEATURE_FMAC
+	select VFP_FEATURE_REGS_S64_D32
+	help
+	  This option signifies the use of a VFP floating-point coprocessor
+	  that supports single- and double-precision operations
+	  (including fused multiply-accumulate) with 32 double-word registers.
+
 config VFP_DP_D32_FP16_FMAC
 	bool
 	select CPU_HAS_VFP

cmake/gcc-m-fpu.cmake

@@ -48,6 +48,14 @@ if("${ARCH}" STREQUAL "arm")
   elseif(CONFIG_CPU_AARCH32_CORTEX_A)
     if(CONFIG_CPU_CORTEX_A7)
       set(GCC_M_FPU vfpv4-d16)
+    elseif(CONFIG_CPU_CORTEX_A9)
+      set(GCC_M_FPU vfpv3)
+      if(NOT CONFIG_VFP_FEATURE_REGS_S64_D32)
+        set(GCC_M_FPU ${GCC_M_FPU}-d16)
+      endif()
+      if(CONFIG_VFP_FEATURE_HALF_PRECISION)
+        set(GCC_M_FPU ${GCC_M_FPU}-fp16)
+      endif()
     endif()
   endif()
 endif()

soc/xlnx/zynq7000/xc7zxxx/Kconfig

@@ -11,3 +11,4 @@ config SOC_SERIES_XC7ZXXX
 	select CPU_CORTEX_A9
 	select SYSCON
 	select ARM_ARCH_TIMER_ERRATUM_740657 if ARM_ARCH_TIMER
+	select VFP_DP_D32_FMAC

soc/xlnx/zynq7000/xc7zxxxs/Kconfig

@@ -11,3 +11,4 @@ config SOC_SERIES_XC7ZXXXS
 	select CPU_CORTEX_A9
 	select SYSCON
 	select ARM_ARCH_TIMER_ERRATUM_740657 if ARM_ARCH_TIMER
+	select VFP_DP_D32_FMAC