arch/hppa: add new architecture

Add support for the Precision Architecture (a.k.a. PA-RISC),
a 32-bit architecture developed by Hewlett Packard.

While at it, add this arch to myself in DEVELOPERS.

Signed-off-by: Vincent Stehlé <vincent.stehle@laposte.net>
Cc: Romain Naour <romain.naour@gmail.com>
Cc: Julien Olivain <ju.o@free.fr>
[Julien: arch "arch/" prefix in commit title]
Signed-off-by: Julien Olivain <ju.o@free.fr>

arch/Config.in

@@ -65,6 +65,15 @@ config BR2_aarch64_be
 	  http://www.arm.com/products/processors/instruction-set-architectures/armv8-architecture.php
 	  http://en.wikipedia.org/wiki/ARM
 
+config BR2_hppa
+	bool "HPPA"
+	select BR2_USE_MMU
+	select BR2_ARCH_HAS_NO_TOOLCHAIN_BUILDROOT
+	help
+	  Precision Architecture (a.k.a. PA-RISC) is a 32-bit
+	  (big endian) architecture developed by Hewlett Packard.
+	  https://en.wikipedia.org/wiki/PA-RISC
+
 config BR2_i386
 	bool "i386"
 	select BR2_USE_MMU
@@ -385,6 +394,10 @@ if BR2_arm || BR2_armeb || BR2_aarch64 || BR2_aarch64_be
 source "arch/Config.in.arm"
 endif
 
+if BR2_hppa
+source "arch/Config.in.hppa"
+endif
+
 if BR2_loongarch64
 source "arch/Config.in.loongarch"
 endif

arch/Config.in.hppa

@@ -0,0 +1,22 @@
+choice
+	prompt "Target Architecture Type"
+	help
+	  Architecture type (or version) to use.
+
+config BR2_parisc10
+	bool "PA-RISC 1.0"
+config BR2_parisc11
+	bool "PA-RISC 1.1"
+endchoice
+
+config BR2_ARCH
+	default "hppa"
+
+config BR2_NORMALIZED_ARCH
+	default "parisc"
+
+config BR2_ENDIAN
+	default "BIG"
+
+config BR2_READELF_ARCH_NAME
+	default "HPPA"

arch/arch.mk.hppa

@@ -0,0 +1,13 @@
+#
+# Configure the GCC_TARGET_ARCH variable.
+#
+
+ifeq ($(BR2_hppa),y)
+
+ifeq ($(BR2_parisc10),y)
+GCC_TARGET_ARCH := 1.0
+else ifeq ($(BR2_parisc11),y)
+GCC_TARGET_ARCH := 1.1
+endif
+
+endif