porting: fix npl to allow NimBLE version bump in RIOT

[haukepetersen]

This PR is a collection of small fixes to NimBLEs porting layer to allow bumping the NimBLE version in RIOT to the newest NimBLE master.

The main changes are composed of:

• fixing the NimBLE porting initialization in nimble_port.c by adapting to the changes in the transport structure
• add hal_system.h, as this file is required by the NimBLE controller now
• used the nrf52_clock_x() functions in ble_phy.c also for the RIOT port
• supress -Wcast-align compiler warnings in os_mbuf.h directly (instead of needing to patch the file in RIOT, which we did so far)

[haukepetersen]

• added one more fix: include "os_cputime.h" for the nrf51 PHY driver
• rebased

[utzig]

Style check summary

Our coding style is here!

porting/nimble/include/os/os_mbuf.h

Details

@@ -133,7 +133,7 @@
 
 /** Get a packet header pointer given an mbuf pointer */
 #define OS_MBUF_PKTHDR(__om) ((struct os_mbuf_pkthdr *)(uintptr_t)  \
-                (void *)((uint8_t *)&(__om)->om_data + sizeof(struct os_mbuf)))
+                              (void *)((uint8_t *)&(__om)->om_data + sizeof(struct os_mbuf)))
 
 /** Given a mbuf packet header pointer, return a pointer to the mbuf */
 #define OS_MBUF_PKTHDR_TO_MBUF(__hdr)   \

[sjanc]

I assume CI will be fixed once RIOT PR goes in too?

[haukepetersen]

I guess so, should be building again as soon as the version in RIOT is updated with RIOT-OS/RIOT#18029

[haukepetersen]

rebased and tried again to fix the style issue pointed out by the style check... Will squash once the style check is happy :-)

[haukepetersen]

squashed, will merge as soon as we have RIOT-OS/RIOT#18029 sorted out - shouldn't be long...