[PATCH] include: fix 'ulong' definition on musl targets

[Sergei Trofimovich]

The build failure was originally reported on arm64-musl
target at https://bugs.gentoo.org/703132. Here is the amd64-musl
variant:

```
$ LANG=C make CROSS_COMPILE=x86_64-gentoo-linux-musl- tools-only_defconfig -j$(nproc)
$ LANG=C make CROSS_COMPILE=x86_64-gentoo-linux-musl- tools-all            -j$(nproc)
...
In file included from tools/env/../../env/flags.c:7,
                 from tools/env/env_flags.c:1:
include/env.h:159:1: error: unknown type name 'ulong'; did you mean 'long'?
  159 | ulong env_get_ulong(const char *name, int base, ulong default_val);
      | ^~~~~
      | long
```

Note: 'ulong' is not defined there.

On glibc 'ulong' comes from <sys/types.h>:

```c
/* Old compatibility names for C types.  */
typedef unsigned long int ulong;
```

On musl it comes from <sys/types.h> as well but from under different guards:

```c
typedef unsigned long u_long, ulong;
```

The change inlines 'ulong' define similar to 'uint' define.

Bug: https://bugs.gentoo.org/703132
Signed-off-by: Sergei Trofimovich <slyfox at gentoo.org>
---
 include/compiler.h   | 2 +-
 include/u-boot/crc.h | 2 ++
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/include/compiler.h b/include/compiler.h
index 29507f9840..90372f239c 100644
--- a/include/compiler.h
+++ b/include/compiler.h
@@ -46,7 +46,6 @@
 # include <byteswap.h>
 #elif defined(__MACH__) || defined(__FreeBSD__)
 # include <machine/endian.h>
-typedef unsigned long ulong;
 #endif
 #ifdef __FreeBSD__
 # include <sys/endian.h> /* htole32 and friends */
@@ -66,6 +65,7 @@ typedef uint8_t __u8;
 typedef uint16_t __u16;
 typedef uint32_t __u32;
 typedef unsigned int uint;
+typedef unsigned long ulong;
 
 #define uswap_16(x) \
 	((((x) & 0xff00) >> 8) | \
diff --git a/include/u-boot/crc.h b/include/u-boot/crc.h
index 1086d2168c..b96b50d98b 100644
--- a/include/u-boot/crc.h
+++ b/include/u-boot/crc.h
@@ -8,6 +8,8 @@
 #ifndef _UBOOT_CRC_H
 #define _UBOOT_CRC_H
 
+#include <compiler.h> /* unit definition */
+
 /**
  * crc8() - Calculate and return CRC-8 of the data
  *
-- 
2.24.1