include/u-boot/crc.h: pull 'uint' definition on musl targets

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)
...
include/u-boot/crc.h:37:44: error: unknown type name 'uint'; did you mean 'int'?
   37 | void crc16_ccitt_wd_buf(const uint8_t *in, uint len,
      |                                            ^~~~
      |                                            int
```

Note: 'uint' is not defined there.

On glibc 'uint' comes from <sys/types.h> and happens to work on most .c files.

The change imports 'uint' declaration from '<compiler.h>'.

Bug: https://bugs.gentoo.org/703132
Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>

include/u-boot/crc.h

@@ -8,6 +8,8 @@
 #ifndef _UBOOT_CRC_H
 #define _UBOOT_CRC_H
 
+#include <compiler.h> /* 'uint*' definitions */
+
 /**
  * crc8() - Calculate and return CRC-8 of the data
  *